I voted for Final Fantasy IX.
That game made me realize how important the old "Medeival, Fantasy" setting, is/was so important to hardcore FFers. Despite FFIV being my SECOND Final Fantasy (I'd play that whenever my brother was hogging our then new PSX at the time), I had never really noticed, until FFIX.
*sniff* Too bad Square has said it themselves, that it will be THE LAST Fantsay-style Final Fantasy game... 🙁
Then again, from what I've read about FFXII, it'll seem a lttile "Fantasy-like".
However, after the crap that was FFX (okay, factor out it being a Phantasy Star II rip-off, it's not THAT bad of a game, I will admit), and FFX-2 (shouldn't have even been made..), I'm kinda iffy on FFXII. But there's part of me that's really looking foward to it.