Those are great, but The Godfather is my favorite example. The book is, honestly, terrible. The prose is bad. It focuses almost exclusively on the salacious - does it need to tell us that many times about the size of Sonny's cock? - and enjoys the violence a bit too much. None of the minor characters leave any impression at all. The movie, though, is... The Godfather. It transcends it's source, without transposing or changing anything - in fact, I suspect it's far more faithful to its historical setting than the novel - more fully than any adaptation I'm aware of.