Here's a simplified guide for you
Final Fantasy: NES and Virtual Console (8-bit), PS1 and GBA (16-bit), PSP and iPhone (High-Res)
Final Fantasy II: PS1 and GBA (16-bit), PSP and iPhone (High-Res)
Final Fantasy III: DS (3D)
Final Fantasy IV: PS1, GBA and Virtual Console (16-bit), DS (3D)
Final Fantasy V: PS1 and GBA (16-bit)
Final Fantasy VI: PS1 and GBA (16-bit)
Final Fantasy VII: PS1, PSN, and PC
Final Fantasy VIII: PS1, PSN, and PC
Final Fantasy IX: PS1 and PSN
Final Fantasy X: PS2
Final Fantasy XI: PS2, PC, and 360
Final Fantasy XII: PS2
Final Fantasy XIII: PS3 and 360
Final Fantasy XIV: PC
If you're going to want to do all of them then FF11 and 14 are going to be a problem, not because they have a monthly fee, but because they're so long. FF11 alone is as long as all the offline ones added together easily. And it's no good to say they don't count, because anyone who's played it will know at least 11 is very much like the early NES FF games, and 12.
Anyway though, if you're happy to do the task whatever, then hopefully the above list should help. O, and on the Virtual Console, FF4 is named FF2, and when FF6 comes out for the Wii, it will be named FF3. Just to confuse things.
