Out of those three, Ruffalo is the one best suited for that role IMO. Though I really can't hold much against Bana for how that played out. Ang Lee just dropped a colossal turd that no actor in that film could have overcome.
I'm slightly warming to the idea of Affleck as Batman, but I still think there were numerous better choices.
Physically, I liked Norton better, but Ruffalo was the far better actor and did things with the part nobody else had done.
For me, he's Banner from now on. I even liked his Iron Man 3 cameo.