Turn based: Legend of Legaia. Also really enjoyed the Mana Khemia games on PS2.
Action: Tales of Graces f and Ys Seven.
Strategy: Valkyria Chronicles and Super Robot Wars OG 2nd.
I see many people mentioned FFXIII battle system... While it did have potential to be good, the fact you can literally just mash X on auto-battle and just shift between Attack>Heal for the whole freaking storyline takes away from its value. The only really fun battles that required actual strategy were Vercingetorix and Long Gui. --- "It's a tradition unique to JRPG fanbases to discuss the virginity of characters." - SetsunaFSeiiei BBCP HYYYYYPE
Golden Sun. It was fun, very fast-paced (random encounters were finished in seconds), looked awesome and Djinn summons. And it had awesome battle themes. --- Dream as if you will live forever, live as if you will die today
Dark Souls. The weight of each move merged action with strategy to reach, in my opinion, the most balanced battle system I've experienced (player vs. enemy of course). The slow pace allowed you to time dodges, blocks and attacks in accordance to the enemies tells in a fashion not so unlike the Punch-Out Series, which I also enjoyed immensely. --- "Lighthouses are more useful than churches" - Benjamin Franklin