I'm getting Cloud next, though I'm never going to actually use him (who was the moron who decided that all his abilities need to charge like spells and that he can't use any of them unless you equip the materia blade on him AND that he starts at level 1?!). Just for completion's sake.
There was a fight near a reservoir where you had to hit some switches and the battle wouldn't end until you did that...so in the PSX version I just killed all the enemies and had my characters cast focus, chant, tailwind, etc., and then start beating each other up to go up in levels...
...well, in the PSP version they changed it so as soon as you killed all the enemies the battle ended even if you didn't step on the switches. Laaaaaaame.