Balthier is the most popular character in the game. He is the super awesome guy
He is in Final Fantasy Tactics as a secret character and he is easy to unlock. He is AWESOME in FFT. He has Mustadios Abilities, the speed of a ninja, and upgraded versions of a thief's steal abilities.
Gabranth and Basch are also very cool.
Anyway, XII seems to be a game that is "like or hate" and I like it because of the fun gameplay and awesome supporting characters. I havent gotten extremely far into the story so I dont know what to say about that, but what I the story I have seen so far was cool and the voice acting is extremely good. Definately give it a try. You might like it