The best and worst of each generation!

We've had "favorite" and "least favorite" polls numerous times, but let's try to decide which FF from each generation is the best and worst for you! if you want to explain why, that's fine! Main entries only. And XV is counted as the same generation as XIII and XIV (so PS3 and PS4) because 1) rule of three and 2) it was originally conceived as an FNC title, so it counts.

NES

Best: Final Fantasy III - I've grown to like it a lot more now that I used the Geomancer instead of the Magus, but it's still a really close tie with FFII.
Worst: Final Fantasy I - not that it's bad, it's just the first one in the series, so there is really not much plot (which II has, with actual characters and events), and the battle system is not as interesting as III's

SNES (TOUGHTEST CALL EVER BECAUSE THEY'RE ALL EXCELLENT)

Best: Final Fantasy VI - the music, the story, the characters, everything just works so well together.
Worst: Final Fantasy IV - BUT that's only because it set the template that all future games built up on. It also easily has the best constrcuted narrative in the series, with very even pacing and tension in all the right places.

PS1

Best: Final Fantasy IX - a phenomenal return to the roots that has some of my favorite elements in the series, period
Worst: Final Fantasy VII - while a good game, I was surprised with how bad the second disc was as I replayed it recently. It's one half pointless padding, one part insane plothole. It's gloriously broken beyond repair.

PS2

Best: Final Fantasy XII - the world, the characters, and the battle system are just exactly what I want. I loved how toned down the melodrama was and how smart the narrative was.
Worst: Final Fantasy X - I just don't like the whole "LOOK AT ALL OF MY FEELS!!!!" attitude Toriyama's games present to me in general. it's not as bad as what comes next, though. And the battle system isn't half bad, though I do miss Ito.

PS3&PS4

Best: Can't comment yet because I haven't played enough XIV and I can't play XV yet, but from what I've seen so far, XV is the easy contender.
Worst: Final Fantasy XIII - I had to force myself to play it. Easily the most boring gameplay experience I've ever had with hallways all around, including character building, and pointless gating of levels. And the characters are just terrible. The story, while it has some potential, is just all the worst parts of X's sentimentalist crap on steroids. Do not want.

NES: FFIII, II
SNES: FFVI, V
PSX: FFVII, VIII
PS2: I won't cheat and use DoC, so FFX, XII
PS3: FNC FFXIII Trilogy, Lightning Returns to be more specific, XIII
PS4: FFXV, Type Zero

PS1
I never touched IX. The game has no appeal to me.
Best: FFVIII while a flawed game that has a hard to learn Junction System, if one is not used to RPGs and/or skips tutorials, this game was my introduction to FF. It took me years to master the Junction System, but once I did everything became a cake walk. I wasn't and still am not a big person for love themed games/stories, but I still manage to enjoy FFVIII's story. Triple Triad is the most addicting side game I have played across the entire FF mainline series. The GFs are cool to me, and I enjoyed all of the Limit Break spamming I got to do later on in the game. The 4 part final boss battle is still my favorite final boss from the games I have played.

Worst: FFVII Imo, FFVII isn't a bad game. However, this game while it does have a story I enjoy and some fun side games, the battle system is just okay to me. It doesn't make me want to go back and play it over and over again. The original English version of the game has some horrible translation issues. Even as a PS1 title, it hasn't aged that well when compared to VIII and IX.

PS2
I never touched XI. It has no appeal to me.
Best - X-2 imo is a much more light hearted game within the series. While I can't say that I enjoyed the story due to being confused by it for so many years, the battle system more than makes up for it. X-2's battle system is easily my favorite out of the FF titles for both the PS1 and PS2 era. The game had a strong focus on attacking as a group and chaining attacks off one another to gain maximum damage. Cat Nip in the original version made the Cloister Trails a lot easier to get through and significantly reduced the threat level from most foes since Gunner Mode's Trigger Happy took advantage of the accessory best. Sadly, Cat Nip has been nerfed for the remastered version, so the trails aren't going to be as easy for me anymore QQ.

Worst FFX: I did enjoy the OST and storyline of FFX. Auron imo is a total badass. Sadly, these things could not be big enough pros for me to forgive the god awful lip sync issues of the English version, and a battle system that I just didn't enjoy at all. I like battle systems that make me think on my toes, which I had no option to do in X at all. X imo, isn't a bad game, but it isn't one of my favs by a long shot either.

PS3
Tried XIV on the PS3 or PS4. Stopped playing after 4 or 5 hours. The game just bored me.
Best FFXIII: The linear structure of the game didn't bother me at all. I really enjoyed the story of the game a lot. Most of the cast had good character development imo, with Hope having the best turnout. I liked the amount of strategy that there was to the more difficult battles. I was constantly experimenting with different party setups because every character had their pros and cons in combat. I also appreciate that the levels were capped during the story line so that way most of the storyline bosses would be challenging for me. I took it as a right of passage. Visually, it's a beautiful game even still today. The combat aspect did have some issues though such as the AI not always doing the most optimal actions and the fact 2 Commandos couldn't focus on one target if multiple ones were on the field. Also, there would be some frame rate drops when magic would fly all over the field. This wasn't something that killed the experience for me, but it was noticeable.

Worst FFXIII-2: Cauis, your awesomeness was the only reason I even finished the game. I don't dislike Noel and Serah, but my interest in the characters was also mild at best. I am glad Serah developed in a way that she wasn't still relying on her older sister by the games end. Noel's story aspect was not bad imo. There are a few tracks I can not stand from the game (the metal Chocobo theme song, and that rap song that got used early in the game). I didn't care for the monster taming thing. It reminded me of Poke'Mon "Gotta Catch Them All". Lightning should have never been on the front cover nor a part of the demo if she was mainly going to be a background character in the game. With me playing the demo, I had the assumption that the game would switch back and forth between Serah and Claire. That didn't end up being the case. Also, putting all of the hardcore bosses behind a paywall? GG SE GG. XIII-2 has been my least favorite game that I have played, and it'll probably always have that spot. The cons far outweigh the pros for me with the title.

PS4
Best FFXV: THE ULTIMATE BROMANCE!!!!!!!! I love the battle system. Ms. Yoko killed it on the soundtrack. I love the "fantasy based on reality theme", and for the most part I think that got achieved. I love the banter, especially when the bros are trash talking each other. I wish the campaign bosses were more difficult, but I am not blaming the dev team given how Japan thought Episode Duscae was too hard with their feedback.... -,-'. I'm still early in the game, but this is hands down my favorite FF mainline game of all time. The 10 year wait was well worth it for me. The game currently does have a lot of technical side problems though. For example, there is some thing called "frame pacing" that effects almost all versions of the game. I'm going to be playing this game for awhile.....

Worst FFVII Remake Part 1: I am pretty sure I'll enjoy the remake more than the original, but I've already played the original game. It just isn't going to be a completely new story. It will be interesting seeing if Advent Children, Crisis Core, and/or Dirge of Cerberus get implemented into the remake at some point. I'm not saying it'll be a bad game, but I'll enjoy it less than FFXV.

Best

NES: FFI
SNES: FFV (even though I didn't play until the PSX era)
PSX: FFVIII
PS2: FFXII

Least Best (I don't hate any of these games, so I won't use "worst")

NES: FFII
SNES: FFMQ
PSX: FFVII
PS2: FFX-2

Personal opinions, not objectively or anything:

NES
Best: FFIII. Adorbs job classes
Worst: FFII. Nothing wrong with it, it's just unremarkable

SNES
Best: V. So much fun, great characters
Worst: VI. Just kinda... meh towards it

PS1
Best: FFIX. BEST. GAME. EVAR.
Worst: FFVII. I hope Aeris gets stabbed OH WAIT

PS2
Best: X-2. I know you said main entries only but it's so hard to decide between X and XII so... X-2 it is!
Worst: Uhh... XI? Was that on PS2, what

PS3
Best: XIV I guess
Worst: XII I guess but I like it still. It's just certainly not the best game

NES

Whooooooo, here comes the unpopular choo choo train or the hipster train or whatever.




Best : Final Fantasy II

BATTLE SYSTEM IS NOT THAT BAD GUYS ! Plus awesome characters for it's time and David Bowie ! Emperor. Dance Magic Dance.

Worst : Final Fantasy III

Final Fantasy V has made this game almost pretty pointless imo, unless you want to complete this game because you want to complete all FF's, or just for the challenge, because, boy, is this game harsh and unforgiving.

Honourable : FFI is pretty damn fun, though it's very simple due to the fact that it's 3 decades old. Though it's worth a play.

SNES

Best : All of them, they're all good. Having to choose between Cecil's, Terra's and Bartz's games between best and worst would be just too be painful. Love them all to death.


Playstation

Best : Final Fantasy IX

This was tough, because I really wanted to put Final Fantasy VIII here, though I have to give credit when credit is due, and FFIX does have amazing storyline, soundtrack and a better battle system than FFVIII Junction System.

Worst : Final Fantasy VII

Whooo * puts on hipster glasses * FF VII I love you, but your story is a mess. A M E S S. It's badly written.

Honourable. Final Fantasy VIII- One of my favourite FFs, Squall is just so damn relatable, also cute love story.


PS2

Best : Final Fantasy X

Really believe that FFX has the best battle system that FF has ever done, also heartwarming plot with some hilarious meme- worthy silly moments.

Worst : Final Fantasy XI

Just not into Online games.

Honourable. Final Fantasy XII. Took me many, many, many, many times to get into. Though eventually, something worked. Just love the female characters that this game has- the strong willed Princess Ashe, the cute Penelo, and the sassy Fran. Don't mind Vaan and Basch either. Battle system is also pretty fun. Story could do with some more warmth and emotion though.


PS3

Best : Final Fantasy XIII-2

Loved the Chrono Trigger feelings this game brought, also loved Caius as a villain and Serah as a main heroine over her sister.

Worst : Lighting Returns

Go away Lightning.

Just leave.

Get out.

Go.

Honourable. Final Fantasy XIII. Don't mind the linear world so much, though it can be either be a make it or break it. Summon System is fun and while most of the characters are highly obnoxious, there is some that make it worth it, like Fang and Sazh.

PS4

Best : Final Fantasy XV

The cute road trip between the choco-bros, the car driving along to old FF tunes, and the new tunes to enjoy as well. Battle system and Open World is not my thing, though the emotions of the story and the characters make it worth it.

Worst : Final Fantasy VII l R

You know that they are going to Advent Children/ DOC/ Crisis Core the heck out of this game and include horrible characters like Genesis in it, you know that they are. I will be surprised and shocked if they actually remake FFVII and just fix the game's bad translations, upgrade the music, and write the OG story better.

I can't really say about the NES because I only played FFI and it's been years ago.

SNES
Best: Final Fantasy VI - It's still my fave. The story and and the characters are simply amazing. And also the music. That game doesn't get old for me.
Worst: Final Fantasy V - I love that game, but I had to choose a worst one for the SNES so here it is. I'm not particularly fond of the job system, but the story and the cast are great.

Playstation
Best: Final Fantasy VII - It was hard to choose between FFVII and FFIX because I really love the story and the characters for both of them, and also the music, but I prefer FFVII's gameplay with the materias.
Worst: Final Fantasy VIII - The story is great, but I don't particularly love the characters in that game, and I'm not a fan of the junction system either.

Playstation 2
Best: Final Fantasy X - It's my second favorite FF game. The story is absolutely amazing, and the characters are great too. There are also many beautiful songs like A Fleeting Dream or To Zanarkand.
Worst: Final Fantasy XI - I'm just not a fan of MMO.

Playstation 3/4
Best: Final Fantasy XV - The story is very addictive, and the characters are very interesting too. Noctis is one of my favorite FF protagonist. And the music is beautiful.
Worst: Final Fantasy XIV - Like I said for FFXI, I don't like the MMO.

SNES
Best: Final Fantasy IV. Honestly I only played this and VI to any great extent, and with VI I played the terrible PS1 port whereas IV I played the very good 3DS port. So it's not really that high a praise.
Worst: Final Fantasy VI for the opposite reasons!

PS1

Best: Final Fantasy IX - Simply the best bunch of character stories in the franchise. Between Zidane, Dagger, Vivi and Eiko there's more depth to the characters than entire games at other points in the series. The game mechanics play it safe rather than trying much in the way of innovation, which is probably for the best considering the nightmare that was Trance.
Worst: Final Fantasy VIII - In many ways this is my second favourite game of the entire franchise. But it's systems are too exploitable, it's plot is too convoluted and it has the worst 'twist' of the series, at least past the PS1 era. So although I prefer it to VII because I like the setting and the soundtrack more, I can't call it a better game.

PS2

Best: Final Fantasy X - Strong plot, second best bunch of characters after IX. The more I play it the more I come to not despise Tidus. He was annoying but actually a really strong character. And Auron is fantastic. And Yuna is wonderful; her speech before the fight with Yunalesca remains one of the most powerful moments in the series for me. I'm also a big, big fan of the CTB to the extent that I am ripping off large chunks of it for my own project.
Worst: Final Fantasy XII - I like XII a lot. The world of Ivalice is rich and beautiful. And as battle systems that break from convention go, the ADB was well designed and gambits were interesting to manage. Hunts were great as well. XII rather suffers from being the only other PS2 FF so it *has* to go in this slot; the lacklustre second half of the story put it here. Also, I didn't care about the characters quite so much as it wasn't as personal a story as X. They were all good characters though.

Except Vaan and Penelo.

PS3 & PS4
Best: Final Fantasy XIII - Poor game overall saved somewhat by Vanille and Fang, who were quite bland characters on their own but together were fairly interesting. The plot was a mess, the RPG systems lacked depth, the majority of the game was one huge corridor, and most of the cast were insufferable. Still, the events that occurred in the game were mostly relevant to the messy story it was trying to tell, which gives it a slight edge over...
Worst: Final Fantasy XV - Quite a fun combat system when taken from moment to moment. But there was even less depth to the RPG systems than XIII had. It's main cast, while decent characters, barely developed throughout the game. The majority of stuff that happens in the story isn't actually relevant to the overall story, and the stuff that is there is an utter mess. The game seems to forget that it has secondary characters at all. Does have some nice dungeons though.

NES:

Best: FF I

Overall, I have a hard time going back and playing the NES era final Fantasies (Not sure why, as I have no trouble with some other NES games like Legend of the Ghost Lion or Mother 3 which I didn't play until the PS3 era of games was already a thing), but this is by far the easiest one to get into.

Worst: Final Fantasy II

Enough people have ripped into this one.


SNES Era

Best: Final Fantasy VI

One of my favorite games of all time. Amazing cast, fun battle system, the split party sections were fantastic and I wish more games did that, and the Villain was outstanding.

Worst: Final Fantasy Mystic Quest..... okay Fine FF V because of your dirty rules.

Seriously though, FF V is great. Best overall generation for Final Fantasy. Even Mystic quest is at least playable and has some good things going for it.

PSX:

Best: FF IX

The Call backs and nostalgia are all great, paired with a fantastic sound track. That asside, despite the slower gameplay early on, the battle system is quite fun, the best mini games of the series, and a damn impressive cast (Even if a couple characters get a bit shafted).

Worst: FF VIII

I think I've bitched enough.

PS2 era was mostly Unimpressive for me, but X was easily the worst, second worst entry in the whole series. And despite some good premises, XII was badly executed for a variety of reasons. FF XI gets the nod because while I'm not a big MMO guy, it was at least fun.

PS3.... let's not get into that generation.

NES: If we are going by literally on the nes. Ive only played 3 but otherwise...
Best: FF2. Wrst:FF1

Snes: Best: FFV Worst: FFIV

PsX Best: ffix worst FFVIII

Ps2: Best FFXII Worst FFX-2 So far.

Current: best: FF XIV. Worst LR FFXIII (used to be my fav of the xiii but.. no anymore)

BEST NES - III, I loved the music and jobs.
WORST NES - II, I've tried a few times to beat it, but haven't. It's the only main numbered one outside XI I haven't beat yet.

BEST SNES - V, it's my favorite Final Fantasy period. I love everything about it. The music, the characters, the jobs.
WORST SNES - IV, just because I have to. This was my first main numbered game. But V and VI are just better.

BEST PS - IX, again it's the music and characters. I liked the throwbacks too.
WORST PS - VIII, I hate Squall.

BEST PS2 - X, I liked the sphere grid and switching out characters on the fly.
WORST PS2 - XI, kind of same with IV. Just because I have to pick. I only played it for a little bit. Attacked a bug and died.

BEST PS3 - XIV, I love this game. Mostly the community and dress-up. Also, I attacked a bug in this one and wiped out it's immediate family.
WORST PS3 - XIII, Lightning sucks too. Hope sucks a little too, awesome magic unit though. Fang and the rest are okay.

SNES
Best: FFIV (I played the DS version). For awhile I actually thought this might be my favorite FF, but I think there's a liiiiittle something missing in it for me. A warmth. But it's really good, and I love Rydia, and omg the song that plays in the Sylph cave.
Worst: FFV. While I'm not a huge fan of FFVI, at least the character design of Terra is smurfing GORGEOUS. I badly want a glam of her outfit in FFXIV. That said, I've given up on FFVI about an hour in so many times. But FFV? I couldn't make it past the first 15 minutes.

PS1
Best: FFIX. This game is almost perfect for me. I do find the first four hours or so (until you beat the Festival of the Hunt and leave Lindblum) slow and kind of dull, but after that...the locations, the music, the story. Beautiful. And just a lot of smurfing fun.
Worst: FFVIII everything about this game is terrible. Well, except Moombas. Moombas are great and I wish they'd show up in other games. The rest of this game can die in a fire, tbh.

PS2
Best: FFX. After FFVII when I was a child, this is the game that re-introduced me to the series. Even though FFIX is my favorite, I consider this to be the objectively best game in the entire series.
Worst: FFXII. I think this game had some real potential, and the music is great. The story is just a smurfing mess, and I really wish that the original director had completed it.

Current
Honestly the only FF game I've played past PS2 is FFXIV, so it's going to be my clear choice. I love this game.
The game I'd be least likely to play and most likely to hate is FFXV.

*All opinions on this post are based on the original versions of each game, except XI, which now has a Trust system.

NES Era
Best: I. Sure, it was buggy, lacked auto targeting, and not very complex, but the game has a charm to it and it's not hard to figure out where to go and what to do. It also started the series, and who knows if we'd have any of the others if that didn't happen. It beats III due to III's incredible difficulty in the last quarter of the game.
Worst: II. A lack of auto targeting, doors to empty rooms, high encounter rates, and bad row mechanics hurt this game badly. When there are things like putting magic users in the back, but limiting magic points and having all attacks fail makes it a mess. If you do equip a bow, you get a huge stat penalty.

SNES Era
Best: IV. The soundtrack is excellent with plenty of great tunes. However, this game does the best job of making the characters' battle roles a part of the story. It crosses over storyline and gameplay flawlessly.
Worst: V. This is a fun game to play and there's so many ways to play it. It's a great game, but IV and VI are excellent. It's like the Bayley to Charlotte and Sasha.

PSX Era:
Best: IX. It's a fun, goofy adventure with characters that are a mix of humans and non-humans. It's just the right mix of light and dark moments.
Worst: VII. This game is heavy throughout, but gets really gloomy at points. The gameplay is mostly fun, but there's a lot of temporary genre changes (like a motorcycle fight game). However, what annoyed me most is that the direction of the button you press often doesn't match which way your character on screen goes.

PS2 Era
Best: XII. This game is fun. I'm a huge fan of the gambit system. Instead of constantly entering commands over and over, I can just set of list of things I want them to do and they carry it out. The system has a ton of flexibility and I really like the idea of MP replenishing as characters walk around, so running out of MP is more of a time penalty than a hard, run back to an inn, issue. XI has similar play, especially now with Trusts, but it takes forever to do anything in XI, so XII wins.
Worst: X. This game annoys to snot out of me. I can deal with Yuna and Rikku, but everyone else is really annoying. Auron is especially bad, as he acts like a know-it-all, pushy jerk quite often. The cutscenes completely ruin the flow of the game and they're unskippable. Voice acting just became a thing and it shows in the quality of it here.

I'll skip the PS3 era, as I haven't played XIV yet and haven't finished XV yet. I do plan to do both someday, though.

I am not going to bother counting the MMOs since I don't really play them.

NES

• Favorite: FFIII - It's a bigger and badder version of FFI with a changeable job class and great swashbuckling stories.
• Least Favorite: FFII - I like FFII, my main beefs with it was the awful inventory system, the bad dungeon design, encounter rooms, and some padding in the mid section of the game.

SNES

• Favorite: VI - Probably wouldn't be here if it wasn't for this game. Changed my views on gaming from just being fun entertainment to seeing it as a medium for art.
• Least Favorite: V - Don't get me wrong, I love V and I do consider it superior in many ways over it's other 16-bit brethren, but IV and VI hold special places in my heart and I'm always up for a new playthrough of each no questions asked. V for some reason has never quite evoked that feeling for me.

PS1

• Favorite: IX - one of the last games in the series to make me question my list. Just thinking about IX gets me feeling all gooey inside despite the problems I do have with it.
• Least Favorite: VII - Not a fan. I don't quite hate it like I used to but it still has too many flaws for me to see it as anything but overrated.

PS2

• Favorite: XII - I love me some Ivalice and I enjoyed exploring the world with it's intriguing cast and political drama. Also the Gambit system kind of ruined A.I. party members for me and even to this day, I wish a game could give me the same level of control as it did when I play games that have A.I. companions.
• Least Favorite: X - I hate Yuna, and I hate the fact the game took one of my favorite myths in Japanese folklore and stretched it out into 40 terribly boring hours of filler and overused JRPG cliches. The gameplay could have saved it had the game bothered to muster up any challenge for the first 30 hours when I was actually interested, instead of waiting for the post game to let the actual fun part of the game begin. Also smurf hating on the orphanage twist, because Tidus being a dead dude's dream is still one of the worst plot twists in the series.

PS3/4

• Favorite: XV - I am not even done with it yet (about the halfway point) but I can honestly say this is better than the XIII trilogy tripe. XV at least remembers that it's a game. The main four have also proven to at least know what human emotion really is and their interactions are quite endearing. I'm not even a huge fan of Action-RPGs (one of my least favorite RPG Sub-genres) and open world style games, and I can still say I've had a blast with both so far.Even if the story does turn out to fail me, I've had more fun with it than I did XIII.
• Least Favorite: XIII - It's not just a bad FF, it's just a bad game in general.

NES era:

Favorite: FF1 - I have a hard time picking between 1 and 3 for my second favorite title in the series, but I'll go with 1 here. I love the game's general level of difficulty, I love how game progression is based around your exploration instead of narrative guided direction, I love the ability to sequence break from the mid game onward, and I love how challenge-friendly the game is. It's probably the series' most pick up and play friendly game for me.

Also, it has a random dragon controlled space station with a War Mech in it. Why is that even a thing? I love it.

Least Favorite: FF2 - Probably my least favorite entry in the franchise, the game was wildly ambitious in all the ways that I love, but fell on its face continually in execution. The world feels small, leveling is tedious, weapons all feel the same, bosses are non-memorable, dead-end doors in dungeons make them the most irritating in the series, and the only characters I find myself liking only briefly accompany the party -- the game simply lacks anything to bring me back to it.

SNES era:

Favorite: FF6 - I have a hard time finding something I dislike about the title. I appreciate how much equipment and unique character abilities play into the game, the open ended second half, the music, and I don't think the game has a single character I actively dislike.

Least favorite: FF5 - I enjoy the battle half of this game, with great customization and some pretty memorable bosses and areas, but I am completely uninterested in the game's story and villain. Lenna is also likely my least favorite party member in the SNES era.

PS1 era:

Favorite: FF7 - Hard pick between this and 8 for me, though I find the Limit system in 7 was much better done than 8s, and I prefer the materia system to junctioning. I also tend to like FF7's cast more than 8s, though both have their duds.

Least favorite: FF9 - This is probably the only game in the series that actively makes me want to play OTHER games in the series while I play it. I do not enjoy my strategic options, the story, the minigames, or most of the characters, and the characters I do appreciate are generally plot irrelevant. I'd like the game less than FF2, but at least nothing about 9 is tedious and I can actually USE characters I like in it. :nod:

PS2 era:

Favorite: FF12 - I don't particularly enjoy the combat system, which is normally an instant fail for me, but I find gambits interesting and love toying with them, which keeps me invested. I also like most of the cast and find the story interesting.

Least favorite: FF10 - This game is like that ride Plucky takes with Hamton's family in the Tiny Toons movie, only you don't have to leave the park as soon as you finally get there. Select aspects of the combat and late game sidequests are the only redeeming elements of this game for me, and that's just not enough to make up for subjecting me to Yuna, Tidus, and Wakka for the whole trip there.

Best:
I - The nostalgic appeal and simplicity of it puts above the rest.
VI - Where the series peaked imo. Best game ever.
VII - Fantastic follow-up to VI, breaking new ground in 3D modeling while still keeping to the traditional elements.
XI - A completely biased pick because I played the smurf out of this game with my wife. A lot of great memories. Story and job system were also very solid.
I guess XIII-2 - Because I only played this and XIII and XIII had too many flaws, most of which (at least gameplay-wise) were fixed in XIII-2

Worst:
II - I just hate that battle system that requires you to beat up your characters to advance them.
V - Nothing against this game but it's up against some juggernauts! Definitely the best game on this 'worst' list.
VIII - The contrived love story and draw magic system bring down an otherwise fun game.
XII - Another solid game, I just liked the other two better. In XII I did tend to get lost in the side quests and then lost interest in continuing (for like 3 years).
XIII - A flawed game in so many ways. It had some high points and generally I enjoyed it but it just felt like a mess of parts pieced together.

FFXV is pretty bad. So bad its foul stench will defile the world for generations to come.