Actually, some movies are so much better than the books they are based on. The Princess Bride, The Phantom of the Opera, Cats...I love all three movies but the books do nothing for me.
But mostly, yes, books trump movies.
I'm doing a course on that at uni at the moment. :) I get to write about how much I hated Francis Ford Coppola's Dracula compared to Bram Stoker's novel. >:D