At the moment:

Final Fantasy (NES)
Final Fantasy III (DS)
Final Fantasy IIUS (SNES)
Final Fantasy IV (PS1)
Final Fantasy IV Advance (GBA)
Final Fantasy V (PS1)
Final Fantasy V Advance (GBA)
Final Fantasy VI (PS1)
Final Fantasy VI Advance (GBA)
Final Fantasy VII (PS1)
Final Fantasy VIII (PS1)
Final Fantasy IX (PS1)
Final Fantasy X (NTSC, PS2)
Final Fantasy X-2 (NTSC, PS2)
Final Fantasy Mystic Quest (SNES)
Final Fantasy Tactics Advance (GBA)

I used to have FFT for the PS1 and FFIIIUS, but they have since been misplaced. Back to bargain hunting...