FF6, no competition.
And I don't count Kingdom Hearts, Chrono Trigger etc as FF games. Sure, they contain similar elements, but that's just because that stuff works.
When someone asks which mario game is the best, I'd be thinking Mario Bros, Mario World etc etc, not Mario Kart, that's a spin-off =p
But even counting all the games on the list my vote still goes for FF6

I had to put FFV...yes I added it to the poll. Loved the story and the Job/Ability system. Five total PCs. Never had to do character fumbling, you made them how you want them.

VI had an excellent story, yes but WAY too many characters. I always ended up with Terra, Celes, Edgar, and Shadow. Two magic users, tools!, and throw **** for awesome damage.

Locke was good when I knew the dungeon had awesome loot.
Strago (that right?), never cared much for blue magic/mages.
Relm I used for all of 45s.
Gau and Umaro were utterly useless
Cyan was..eh but his sword techs took too long.
Sabin was a washed up Street Fighter character. If you were good at SF, I suppose he was clutch but I always sucked at SF
Mog's dances only worked (well) in certain areas.

IV took too long. It seemed to just drag on.
VII good story but needs less anime. Easy to get ridiculously overpowered. Seriously. I beat Sephiroth in 5 mins.
VIII God did I really want to punch Squall. Many annoying characters (I'm looking at you Selphie & Zell)
IX A breath of fresh air from Anime Final Fantasy. Old school FF with (then) new school graphics.
X, X-2, XII I need a PS2...or find a way to jerry-rig my PS3 to play PS2 games.

Setzer, edgar, Sabin, and whoever i felt like would be my normal party

not nearly enough FF3/6 votes damnit

Mystic Quest will always hold a special place in my heart. It was my first RPG.

I loved that in FF6 there was often times where you would be required to use every character, split into teams and needing to switch between them for puzzle/defense purposes.
Really enjoyed those moments.

VIII, because of the Junction System.

100x PAIN on MY GUNBLADE.

Agreed

I'm surprised 8 has so many votes. The series died with me halfway through 8. I still gave 9 a shot though, but didn't get beyond disc 1

Because VIII was great! Ok, so it was all angsty teenagers but the junction system meant you could make BEASTLY characters. It was rocksauce.

VIII was fantastic all over.

I couldn't stand 8. I hated the junctioning system, I couldn't stand the melodramatic teenage love story, and I hated all the characters except for Irvine, and he barely had any involvement in the story. Every time Selphie came on screen I wanted to stab myself.

That's odd because I loved pretty much everything apart from Irvine.