I didn't think battle systems mattered. What really counts is the game itself. Here's a few from the top of my head that I recommend.

Kingdom Hearts I & II
Grandia 2
Shadow Hearts
Legaia 2: Duel Saga
Wild Arms 3
Valkyrie Profile: Lenneth (PSP)
Baldur's Gate: Dark Alliance I & II
Diablo II

Be warned though Valkyrie Profile is extremely addictive.