I would have to say VIII and by a wide margin actually. Then again, I happened to like VIII.

Story:
VIII
Okay, VIII's plot is bat--crazy. It starts off really intriguing with child soldiers qwelling international disputes and a supernatural evil taking over a militant country to start the games equivalent of WWI, not to mention the eerie dream sequences where your party live the lives of enemy soldiers from 20 years ago. Then Disc 2 starts and we're faced with the most BS version of a wall banger plot twists and time travel crap that the player loses any sense of being able to take anything storywise serious. At the same time though, the story has this kinda odd train wreck appeal. You know its ridiculous but you just can't turn away and well... its entertaining in a sick way. The only exception to this is Laguna's story which for all intents and purposes is very good if a bit jumbled since you are literally dropping into event in a 20 year period with little context of what's actually going on. Laguna is a fun character and the story of his life and its comical ending are quite enjoyable.

X-2
What plot? Okay seriously now, X-2 is a story mission game and well... SE can't do them well. The main plot is lost in the riff-raff of mini-games and silly concerts. Most of Paine's plot is told in a very loose way and you hardly ever get to know any of the new characters except Shuyin and Lenne without collecting asinine McGuffins from every corner. What main story their is here, basically is built around retconning the only decent thing about FFX which was its tragic (though pretty sappy) ending. Basically the nuances of the plot are wasted on first time players or people who didn't like FFX. The overall "girly feel" of the game (which is over-exaggerated) turns off many of the FFX fans as well, but then again its hard to be justifying this game to a girlfriend if she walks into you playing as a bunch of scantily clad chicks whose every action leads to some cheesecake fan service. You know what its like to have your parents walk in to the room when Paine is transforming into the Lady Luck dressphere? At least my dad bought me some decent porn videos afterwards...

Overall: Porn is good but train-wrecks tend to stay with you longer. Seriously, VIII has a bad plot but its better than a game whose plot only makes up 10% of the content (Assuming you picked up all the Crimson Spheres) with the rest being bubbly filler that will make you throw up. On a more serious note though, VIII has a ton of memorable moments in it like the opening the Assassination attempt on Edea, the battle between the Gardens, and Rinoa and Squall drifting in space. VIII has a lot of memorable moments, whereas I can't really think of anything from X-2 except the cringe worth song scenes and the BS retcon Super Happy ending. VIII wins.

Characters:
FFVIII
Like the story, VIII starts pretty strong and then decides to drop the entire cast except three people after you get halfway through disc 2. Which is a shame cause Zell, Seifer, Quistis, Kiros, Ward, and most of the "villains" could have been really interesting and instead feel like cardboard cutouts. The same can't be said for Squall and Laguna; Squall especially has great character growth and you really get to see the game through his eyes. Yes, he goes all sappy once he decides he loves Rinoa but I have yet to meet a guy who says he's met the love of his life and not do a 180 in personality for it. Even then he still sticks to his calm and snarky self throughout the rest of the game. Even if the cast never does get the growth they deserve, its not like they are bad characters, shirt tempered jock Zell, Bossy but unsure Quistis, Womanizing Irvine, and obnoxious Selphie are still entertaining to watch and their relationship with Squall is what brings out the humor of the game as you watch the party constantly trying to cheer him up while he's only thinking about drowning them in the nearest body of water.

X-2
Let's take Yuna, who already has the personality of cardboard and make her the main character. She constantly talks about finally "growing up" and "living for herself" and no longer letting "other people dictate her life" and then proceeds to spend the rest of the game helping ever human, Ronso, Guado, and rock in Spira that happens to have a sad sob story, so basically her character growth is mostly hypocrisy . Let's throw in Rikku who is horribly obnoxious and let's fill her up with even more sugar, make her legal, and by being legal, make her dress like a smurfing whore... Then there is Lulu... I mean Paine, who is basically Lulu in all ways except technically being younger and being a warrior instead of a mage. Paine, really doesn't do anything that helps her character not come off as a Lulu rip-off and never really justifies her presence in the story beyond just happening to be connected to the three new guys. Speaking of which, Nooj, is a jerk, the Yevon guy is nice but associated with a bunch of jerks and gets little screen-time, and Bikkal is pretty awesome but gets less screen time than O'aka, the Yevon guy, and Maechen two of which are npcs and have nothing to do with the main plot. Lebalnc and her gang, are just plain pathetic and only help to drive the terrible fan service of the game even more. Shuyin's back-story only allows him to be sympathetic to people who wear their hearts on their sleeves, the rest find him pretty pathetic and mostly at fault for his own problems. Lenne is basically another Yuna which means she might as well be drywall with a wig and skimpy dress cause that's how much personality she has. So seeing as how I hate pretty much everyone in the cast... yeah...

Overall: VIII's cast fails to live up to its potential, but at least they are interesting and entertaining as opposed to X-2's cast which is void of any major character that is likable. When the NPC's of your game are more interesting and likable than the main cast, I feel that's a major problem. VIII wins.

Gameplay:
VIII
So many posts and rants about the Junction system exist that books could probably be written about it if someone was bored enough to collect all of it. If you found the system tedious, then you weren't using it right, if you found it too easy to exploit then you understood it too well and you truly understand the systems real weakness and if you found it both ways,m well this wasn't your game now is it?
I like elements of the system, I like the concept of using magic to buffer abilities and I feel it actually works really well until the game starts introducing the support skills that jack up all your stats into god-mode territory. If you find VIII too easy but don't want to do one of the silly challenges, I simply suggest you ignore any of the stat boosting support abilites, the difference is between doing 2500-3000 damage to doing 9999 when your party looks at a monster funny.

I actually enjoy drawing from enemies cause it actually makes random encounters a bit more important and makes the player actually stop and think for a moment instead of just mashing X while reading a book or surfing the net for CloudXSephiroth slash fics (you know who you are) which is pretty fun for me at least and I actually just like the overall concept of siphoning strength from your enemies. I really wish it was explored more in the story... Oh well. The downs side of all of this is that magic is only useful as a stat booster. Even with a high MAG stat and support boosting skills, Magic is pathetic in terms of damage which in a way helps deter players from using it to lower stats (even if the lowering is negligible) but I feel it takes away too many options from the player.

GFs were a disaster, its almost impossible to get them killed and they can get so powerful very quickly that they end up being a crutch for players who try avoiding the Junction System with its weird menus and fear of doing tedious magic drawing cause you don't bother to use the refining skill to get rid of all those seemingly useless items in your inventory that's taking up space... . Boosting gives them an interactive feel but after awhile it just gets really obnoxious and tedious, especially when you realize a simple use of Mad Rush will annihilate everything in mere moments as opposed to trying to mash X to get an extra damage for your GFs. They are too easy to exploit in the beginning and in terms of damage output, they are useless by the end of the first disc cause you can jack up your power that quickly.

Refining... is broken. I don;t think I need to say anything else here. Weapon customization seems like a cool concept til you realize its useless except for two characters, Squall who uses it to get Limit Breaks and Selphie whose final weapon gives her a max Hit rate, which seems really spectacular if it wasn't for the fact that Squall's weapons all have max Hit from the get go and an ability to score artificial critical hits...

Overall, the main problem I feel VIII's system has is that it is too easy to exploit and lets face it, god-mode is only fun for the first few hours before it becomes boring. Sure monsters level up with the player but all that really means is that they get more HP and it just makes normal encounters take forever cause even a level 100 monster can't hurt a well junctioned party but thanks to the damage caps, it still takes forever to kill the damn thing. Really, you need to play the game in moderation to enjoy it.

X-2
X-2 brings together FFIII's Job class system, a form of FFV's sub-class system, and VI's Relic system. All three are systems I really like, so what in gods name went wrong? Well first off, you need to switch off the cutscene for dress changes cause they are tedious and ultimately stupid fan service but the other problem comes from the fact that the Dress sphere system is nowhere near as balanced as any of the Job class systems. Who in gods name bothers using most of the dress spheres beyond the simple idea of the novelty of them when you have Alchemist, Gun Mage, and Dark Knight who are all so horribly unbalanced that it makes beating everything but the hardest challenges of the game (and still chances are you will be using them)? Don't even get me started on the game breaking qualities of the Mascot class...

Warrior - Does not hit as hard as it should and even when exploiting elemental weaknesses with the elemental sword attacks, it still feels like I'm only getting a slight damage increase as opposed to something useful, so I might as well just save the MP and the time by just mashing X.

Thief - Can't do damage to save its life even when adding both its attacks since it attacks twice. Its steal abilites are interesting but ultimately useless except for future plans for your Alchemist.

Bard (smurf its actual name) - Mostly a novelty class that doesn't grant really spectacular bonuses, you are better off using a White Mage or having another offensive class.

Berserker - Has mostly useless skills and its high offensive power is painfully impotent due to the classes abysmal hit rate. Even then, it still can't out damage the Dark Knight.

White Mage/Black Mage - Useful in the beginning of the game except for the fact X-2 kept X's BS idea of nerfing mages by making most of their skills single target making the White Mage a terrible emergency aid character and the Black Mage is almost all but useless. Throw in the fact that the Alchemist can do both of their jobs at the same time with little to no MP cost and time use... Yeah....

Samurai - X-2 has to have the worst version of this class in the series which is a shame cause its actually my favorite class in the series. Can barely do more damage than the warrior, heavily skill reliantl, and terribly HP for a melee class, considering you get the Dark Knight class before this....

This is just to name a few... The thing about all the other FF games with job classes, is that everything is balanced enough that you can go into the final battle with using starting classes (okay... maybe not FFIIIj) but overall, the newer classes simply offered alternate play-styles as opposed to just overall superiority. The single spell target mechanics alone nerf the mage classes, and X-2 might have the most broken version of the Dark Knight in the series, seeing as how they have pretty high HP, good defense (for a DK) high attack power and several skills that make random encounters feel more like a chore, not to mention immunity to almost all the games status ailments. Sure they are slow but they are smurfing tanks with nukes strapped to them. Alchemist can do high magic based damage and ridiculous buffing and Gun Mages not only get abilites that give them damage bonuses (which is actually significant for them) but also get several broken Blue Mage skills that allow you to waltz through battles.

I was really trying these classes and I just kept getting annoyed that I always found myself resorting back to the same party cause the other classes are not nearly as fun or useful to use. Gunner gets a bit of longevity for exploiting the bonus damage system with the ATB but even then I hardly found the damage to be terribly noticeable.

The sub-class system presents itself through the garment grid and the Relic system, the problem is that it only really opens up later in the game, its dependent on you actually mastering the classes, and realizing early on that half the classes are useless so why in gods name would I want their abilites, not to mention for the case of the Garment grid you have to tediously switch through different classes to get the abilties cause someone over at Square thought this stupid idea might be fun.

In fact, the Garment Grid system pretty much destroys the entire point of the new ATB system which was trying to put the Action back into the Battle system by making them go faster, which is a pretty moot point when you are constantly going into menus so you can waste three or four turns transforming into different classes so you can get the two abilites you need to end this fight quickly when you could have spent those turns just mashing X or using the Holy Trinity'sDark Knight, Gun Mage, and Alchemist abilities to wipe them all out. Considering fan favorite spells like Holy, Flare and Ultima can only be obtained by using this ridiculous system is just more salt in the wounds.

The relics are obnoxious cause most of them grant one ability like the wonderfully useful Fire Ring that gives a character the Fire spell and only the Fire Spell. This is the kinda crap you will be getting for half the game, the sad thing is, due to the game's funky stat system (I swear the creators were listening to all the complaints about X's poor stat system and algorithms) you will mostly be using ther Relic system as a makeshift armor system to compensate for your parties poor stats, attaching items that raise Vigor and Defense by 50 points or occasionally using one to gain more XP, why bother using the system beyond a glorified armory?

The ATB system is fast but only because your party attacks simultaneously instead of waiting for someone to go first, it still suffers from the majority of skills having long loading times and while you can time it to have a character constantly on the offense, you are basically still making your party take turns so how is this any different from the old system again? At least XII got it right...

Overall: FFV wins, cause lets face it, this is as good as its going to get... well except for FFTactics, it also wins.

Mini-games:
VIII
You only get a two, an obnoxious Chocobo game that was o unremarkable that most people forget it even exists, and Triple Triad which is so addicting and good that I know people who hate VIII but still play it for this mini-game.

X-2
This game has a ton of them but most notable is Sphere Break which surprisingly became my favorite game in the game. The Lightning towers are kinda fun but frustrating, blitzball still sucks, the chocobo game isn't really any fun and if there are any others, they obviously didn't leave much of an impression on me...

Overall:
I'm going to have to give this to FFVIII cause I was really hoping the game Triple Triad would be made into a game to be brought over here outside of Japan. I even enjoy the rules even if Random kinda throws a wrench into everything but still... its a real sense of accomplishment when you actually win those battles by exploiting all the rules. This is not to say X-2 is bad at this, Sphere Break is just as enjoyable, the rest not so much...

Overall Winner:
FFVIII, yes its far from perfect and it probably does take an odd masochist to enjoy it but the same can easily be said of the other entry. Still, I think there is just more substance to VIII, X-2 does have better gameplay mechanics but its filled with such annoying qualities that it ultimately sucked any joy I may have had in it whereas I can still have fun playing through VIII even if I have to handicap myself to do it. VIII also has the better story and cast, yes its poorly written and god knows the most die hard fans have misinterpreted it and taken it to some extreme places but there are still parts of it that are very enjoyable and the character study of Squall is probably one of the best in the series. Not to mention this is the only game that Nojima did exclusive writing for that I actually like.