I'm actually a fan of the Secret of Mana/Seiken Dentetsu 3 battle system.
Likes:
Being able to fight, dodge, and run away in real time makes the system a lot more gameplay intensive. You actually have to pay significantly more attention to how your enemies are moving, how to position your party members, and what weapons (Melee, Mid-range, and Long-Range) you are using. The progression feels fairly natural, and going back to earlier areas really gives you a sense of how much stronger you've become.
Dislikes:
Magic is absurdly broken. Bosses become a chain-spell DPS race with the boss, and just pray you don't run out of MP, because your weapons do literally nothing. Most of the regular enemies have very simple A.I. and can be stunlocked indefinitely. If you know what you're doing, and are abusing magic to its full potential, the game is way too easy, if you tried to play without ever using magic, you would most likely have to grind 5-7 levels per boss.
Verdict:
The battle system in itself is fun and challenging, but needs major balancing changes. Giving players any good reason to care about their physical attacks would definitely be priority number one.