VIII, there really is no contest.
i kind of get where the haters and fanboys are coming from now, but for me personally, this game was about as close to perfection as a game can get.
the graphics (for its time), the story, the characters, the music, the pacing, all scored perfect 10's. this maybe because it was my first (you never forget your first
real rpg, and it really left an impression on me.
shit, just THINKING about the Battle of the Gardens FMV gives me goosebumps.
VII certainly was amazing, and ive never finished it. playing it as i am typing.
IX i only played till the end of the first disc. i kind of ignored it for years, and i will probably replay it soon. its jarring, especially if you've just come frome VII or VIII, but it really grows on you. certainly worthy of the praise it has received in this thread
X as well, fuck what a soundtrack. i learnt To Zanarkand on guitar!
also, honorable mention to Tactics, and i guess Kingdom Hearts?