I always loved how people like Jon Voight and Laurence Olivier shocked you every time they came on-screen. They were so different each time. That's what I hope to do with acting - be the chameleon and not get stuck in a type.
I know it sounds earnest, but I do really feel in my bones that acting is just a small part of the equation when you are making a movie. The director really is in charge. Actors are as important or unimportant as the rest of the people around them.