In nearly every FF, there is a clear-cut Hero and Heroine. For example FFIX, Zidane and Garnet, FFX, Tidus and Yuna, FFVIII, Squall and Rinoa, etc. But I think, in FFXII, there is no clear-cut Hero/Heroine combo. Instinct would say Vaan and Ashe, but personally, I don't agree.
I think that the Hero of FFXII is Balthier, purely because I think he has more to do with the story than Vaan, and he performs a lot more heroic acts, whereas Vaan.......well......
The Heroine has got to be Penelo. Obviously Ashe has a lot more to do with the story, but I think the story is told more often from Penelos view and focuses a lot more on how things will affect her. That's just my opinion though. What does everyone else think?