Been busy with school and forgot to post in this but I'll give you my :twocents: as the forums resident Persona fan.

Persona 1 - The PSP version is definetly the way to go but I should definetly warn you that this title is radically different from the other entries and is designed to be more like a old school RPG. Steep difficulty curve combined with a customization system that may require Gamfaqs to be your best friend. The game has a tendency to only kinda tell you where you need to go but thankfully, the PSP version actually has a workable overworld map so you probably won't get lost as often as I used to in the original.

The battle engine takes a bit of getting used to... unlike most RPGs, your weapons have range and its actually more limited than you would think. Bascially, if your character uses a sword he can only attack what's directly in fron of him, a bow user can only attack enemies a great distance (back row) and so forth, guns have a greater range but it takes a while to acquire them but luckily magic can target everything but you have to be careful cause the enemies (and Personas) have strict elemental properties that give them their strengths and weaknesses (think Pokemon). The real draw to this title is the conversation system, unlike most non-SMT rpgs, you can actually talk to enemy monsters and negotiate with them. You can talk them into giving you money, leaving, you can scare or enrage them changing their combat capabilities or you can befriend them and attain their card which you use to create new Personas. This part is the driving aspect of the game. Each character has their own personality and thus their own way of communicating with demons meaning if one character is failing at negotiations it might be better to switch to another.

The main problem with P1 is that its plot is downright weird and more B-Movie than anything (which I think is great but some people like a more serious story *looks at NeoCracker*) and the gameplay seems restricted and very "old". I can't exactly recommend it as a first entry for the series as it requires eclectic tastes.

Persona 2 (Innocent Sin and Eternal Punishment), this entry was split into two games and regretfully part one has never made it out of Japan outside of emulation. This entry throws out the original games stifling battle system for something really awesome. The normal combat proceeds like any normal modern RPG where your party is free to attack anyone they damn well please but the two biggest changes come from the introduction of Fusion attacks and the new conversation system. The game takes a chapter our of Chrono Trigger/Suikoden and allows you to combine abilites to create bigger attacks but unlike the titles listed, its relegated to what spells you have and the order you use them in. Basically Fire + Fire + Wind creates Fire Tornado spell, the spells have to be cast in that order (which is possible cause the game allows you to change the turn order of your party though it may take time to cast if the first caster is slow...) and as long as your persona has the spells you can cast this fusion spell meaning you can keep powerful abilites but still trade in your obsolete weak Persona's for better ones. The conversation system also returns and allows you to combine character to have them double team a monster on negotiations. Most of the conversations are hilarious.

The driving force behind P2 is called Kotodama, the mystic belief in the power of words or in this games case, the power of rumors. Basically, in the story, rumors are starting to become true and the game starts with a focus on a figure known as the Joker who has the power to grant wishes (Innocent Sin) or murders your enemies (Eternal Punishment). The game goes into some truly B-Movie bizarre territory but has enough grit and actually horrific moments to make it come off much more serious than its predecessor. If you can get your hands on the two games I highly recommend them as they are debatably my favorite entry in the series next to P3.

P3 is the "FFVII of the Persona series" streamlined, user friendly, and the entry that made the mainstream market notice the series existence. It is my other contender for best entry as it does bring in a lot of fresh ideas.

The conversation system is dropped and your party is restricted to using one Persona for each character while only your main character has the ability to switch out Persona's. You also can only control your main while AI deals with the rest of your party. Its not that bad as it sounds, the AI is actually really good as long as you remember to scan the enemies for their weaknesses. This even works on bosses whome you can't successfully scan so yes the AI can take care of itself, especially in the special edition FES version.
You play a group of High school kids who discover their is a "missing hour" in the day that most people are unaware of called the Dark Hour, in the Dark Hour, most people turn into coffins and sleep through it while monsterous creatures called shadow roam the world and feast on the life force of people they call into the Dark Hour. Those aware of the Dark Hour sometimes have the ability to manifest their psyches and create Persona's that can combat the Shadows. They do this by using an item called the Evoker (which looks like a gun) and shoot themselves into the head, basically ritualistic suicide of the conscious to bring out the true unconscious self. Combat uses the Press Turn system, basically if your character hits an enemy with an elemental weakness or critical hit it knocks them down (as well as big damage) and allows that character go have another turn. If you are able to knock all the enemies down you gain the option to do a big party attack that does huge damage to all enemies. Thus bringing the right party and Persona's is incredibly important (also types of physical attacks count as different types so what your characters ue as weapons is also important), so you have to constantly be fusing Personas and gaining new ones that help your cause. Just be careful about elemental weaknesses cause the enemies can exploit your weaknesses and get extra turns as well. There is a lot of strategy for combat.

Your main character is given one year to live at the start of the game and lives out his days as a semi normal high school student and fihts demons at night. In the day time you have to listen to lectures, pass exams and make friends. The heart of the game comes from the bonds you build with your daytime cohorts. Each friend you make is associated with a Tarot Arcana (same as your Personas) as you get closer to your new friends, you gain experience bonuses for leveling your Personas thus giving you better chances at completing Tarturus and story missions. You basically have to manage how you spend your time, do you do sports today or take that cute girl from the Student Council on a date? Should your spend your evenings studying to raise your grades or should you venture into Tartarus and level your party? The theme of the game is Memento Mori which roughly means "remember you are mortal" and the choices you make each day matter and cannot be unmade once you have made them. So basically its one year in the life of a student who fights demons and discover the truth behind the "Dark Hour".

P4 takes the system from P3 and vastly improves some of it while hindering others. The "social" aspect of the game is much more fleshed out and allows for better options and replay value. You can actually get part time jobs and earn money and some of your social links actually raise your social stats as well. The game is far more story driven than P3 and thus the social aspect can feel hectic and downright daunting at times. Instead of the one huge dungeon and minor story dungeons from P3, there are multiple big story dungeons that have amusing themes.

You can control your whole party now (which is good cause the AI for this game is terrible) but even better you can actually control what your party members retain ability wise so you no longer have to deal with a party member replacing a good spell with a status spell that you know will never hit... They also bring in a system that allows you to avoid the elemental weaknesses to a degree. The difficulty has also been revved up a bit as well.

Course I feel the combat part of the game has some issues, you will be grinding for money alot cause its expensive to buy equipment and fuse Personas and since shadow barely drop money and the items they drop to sell for money is never enough to compensate for the huge price increases, get ready to grind and become acquainted with your part time jobs. It gets really ugly towards the end of the game. Also, the game streamlined physical attacks into one property and then decided to make only a few enemies actually weak to it crippling one character from the get go. They also changed the rules of knockdown as it is now a status called dizzy. If you knock an enemy down they can get back up their next turn and still take their turn unlike P3 where getting up counted as their turn. If you hit the enemy with their weakness while they are on the ground this knocks them into the dizzy status and allows you to go on as business as usual. This is okay for normal encounters as it allows you to do big damage and win quickly but becomes a problem in boss fights as most don't have weaknesses, so trying to exploit a knockdown for healing and buffing becomes a moot gesture cause the boss can quickly get back up and raise heavenly death upon you. Its a shame to see a well polished system get nerfed a bit and overall, the system really benefits the game more than you so prepare for more MegaTen deaths.

There are more changes in this game but I'm running out of time so in a nutshell P2 and P3 are must play, P4 is a pretty good title as well, P1 is the iffy "love it or hate it" title.