Yeah, did you know that PSX CDs can be played on PS2 (supposedly, at least)

I'd definitely suggest La Pucelle like...a person up there...said. La Pucelle is revolutionary, funny, cliche, and fun to play. I'd discourage you into Front Mission 4, nothing interesting there. Bahamut Lagoon is very very good, until you turn every dragon into dark dragons. But Bahamut Lagoon isnt available in English, I think, not too sure though. Hoshigami for PSX is quite similiar to FFT, the main character even look similiar, and gameplay is revolutionary. Onimusha Tactics for GBA, I havent played it myself but Metatron said its his favourite strategy game after FFT, and he recommended it to me. It has to be good if he said it is. It has nothing to do with onimusha the game for PS2, he said.

So in order of greatness (to me):
-Bahamut Lagoon
-La Pucelle
-Onimusha Tactics
-Hoshigami