GBA version all the way....Besides the fact I like the portable, the extra freatures are awesome. The Gladiator class is nice, and the extra dungeon gives you a reason to test out all your characters with all the jobs mastered. The PS1 (PSX is actually a system on its own having very little to do with the PS1) version is nice, but I like to advance version better.

Then again for the same price you either get the advance version, or the PS1 version with an extra copy of FFVI...So the PS1 version is the better deal....