Here's my list that I've beaten:

FF Mystic Quest (SNES Rom)
FF Adventure (GB)
FFLegend I (GB)
FFLegend II (GB ROM)
FFLegend III (GB)
FF Tactics (PS)
FF Tactics Advance (GBA ROM)
FF1 (NES/Origins)
FF2 (NES ROM)
FF3 (NES ROM)
FF4 (SNES/Chronicles)
FF5 (SNES ROM)
FF6 (SNES ROM/Anthology)
FF7 (PS1)
FF8 (PS1/PC)
FF9 (PS1)

I'm working on FFX right now (im at the thunder plains :P) and I havn't even touched FF2 on Origins, I plan to after I rox FFX.