This is a tough one. Purely from a gameplay standpoint 10-2 is the best, but it has arguably the dumbest story of the whole franchise, not to mention tries to a continue a story that definitely did not need to be continued. I don't hate FF8 (not anymore anyway) but I'm not really a fan of it either. It has certain qualities that I like but it's still my least favorite of the PS1 FFs.