FFX-2, because it's the only one that was a true FF game. FFXI..online and not out here yet anyway, plus I play RO so I don't need to play it really =P (especially if I have to pay to play it =P).

FF:CC I like playing multiplayer, and I like a lot of things about it, it's cuuuute, and it has really nice music, and OMG MOOGLES THAT ARE DRUNK AND FALL OVER and it's kinda fun, buuut I think it gets a bit samey and boring after a while, and probably would even more if I played it single player.

FFX-2 was fun, although I didn't like it quite as much as I thought I would.