With the exception of FFV I played all of them to some extent, but only beaten a handful. The only reason I never played V was coz I dont actually own a copy of...but thanks to PSN I can now play that too.
Blech. The PS1 versions of the SNES FFs are so bad.
You're better off trying to track down a copy of FFV Advance (the definitive version of the game, at least in the US). A used copy doesn't cost all that much.