I mentioned this the other day [
SPOILERS if you haven't seen Back to the Future yet!]
You know what makes this scene work? So many directors/editors would have just given us a long, angsty close up of George wrestling with his conscience. But BTTF's creators knew you had to keep the camera mostly on Lorraine and Marty, so we can understand what's at stake, and share their point of view. They don't know whether George will save the day, and therefore neither do we the audience. THEN you cut to George, revealed as our hero, and we ALL breath a sigh of relief. An ideal example of the language of film right here.