Love the Final Fantasy series.
To my shame, I've only ever played X, X-2 and XII.
The very first game I saw was my step-brother playing VII - and I just didn't have a clue what he was doing (he was running through some hovel, then up some massive sky-scraper, scared witless of the guards...that didn't seem to do anything whatsoever - as in not even move). So I never played it myself, apart from when he said "try this out" (a battle in some underground dungeon versus a Mech-like thingy, with Barret, Cloud and some girl).
X absolutely stunned me. I thought the gameplay was awesome, and the characters interesting - but I could never level-up the party, and the sphereboard thingy still confuses me (I felt bad not having Tidus in my party, and if you wanted to summon you needed Yuna, and with those two you needed a heavy-hitter like Auron, so Wakka, Rikku, Lulu and to a lesser extent Khimari (though he stood in for whoever fell first) never really got battle/training time. My first copy of the game kept freezing on "Lake Macalania Bottom", but I got a new one about 9 months ago so I might give it another go. Only bad point was it was one of my first PS2 games, so I expected every other game to look as good...
X-2 I found quite cool, but once I got the overdrives/whatever they're called, I found it hard to level up the "normal" girls. Plus the difficulty in completing even the initial dresspheres, let alone the others you find (and having to do things in *just* theright order to be able to get them all) - especially Sonsgtress, since it makes the character so weak, was a grind-pain. Still, the missions were kinda fun and the plot engrossing.
XII I love, I'm not sure why. I think it's because of the sandbox nature (by having visible enemies it's a little more free-roaming, plus you don't get that pain-in-the-ears sound of smashing glass whenever you get attacked) and the combat system, whilst taking a while to get to grips with, is quite intuitive, and it's nice to be able to get your characters to operate independantly (since it's "active battle" you can save time by *not* having to shuffle through all the characters to cast an ability/spell/item, potentially saving your bacon). The insta-death nature of some areas, when underlevelled, is really annoying though, and the grind gets repetitive - but the chaining means that it is at least rewarding (such as in the Vera woods, where you can attack the Couri all day long, and by the time you get to a 100-chain you've levelled up a fair bit and have loads of money/rare items that sell for loads. The Bazaar is fun, but I always managed to find items I'd just bought in a shop after I'd used said item for a levelling-up chain. Keeping your armour topped up (to prevent the aforementioned insta-death battles) gets expensive too. Plus I can never choose decent equipment options for the characters, and usually end up wanting to swap them after investing *loads* of experience in abilities/weapons of one "class". I also found I never really used the Espers, as I had bad experiences with the first one (the fire one...that couldn't even beat off a load of fire-weak flans in the Luhsu[sp?] mines). If anyone has any XII team tips/builds and would care to PM them my way I'd be quite grateful.
Wow, sorry for the wall-o'-text, this topic has got me really wanting to play through my games again. But which? X or XII? Argh, decisions!