Mines Is
Xenogears because of the insane combo moves you can pull off, 2 different types of battles systems One where you fight fist to fist and one where you can use the gears, Epic battle theme, Citan with a sword.
Tales of Vesperia because it is sooooooooo action-packed and there is a huge amount of customization, hundreds of different arts and spells you can pull off, super insane combos, Burst Arts and Mystic Arts(kind of like the limit breaks of the game) and 4 player co-op so you can enjoy the action with your friends.The battle system can be as complex or as simple as the player wants it to be.
whats yours?