Go with the GBA version, if it's possible for you. It has a bunch of new content, a slightly better, reworked translation, though the sound quality is a bit weaker than the original SNES version. Having played both the GBA and SNES version, I can say I would go with the former, but the SNES one is actually still very good. From what I heard, I'd stay away from the PSX version - sure, they added some CGI cutscenes, but the load-times are reportefly unbearable. You can still watch the scenes on youtube