I saw someone walking around with a tee shirt that said, "The book was better." Haha! I was just talking to Bee about this though, and we agreed that sometimes the movie can be as good as (or better) than the source material.
She said that Gone Girl was as good as the book, and Chicago the movie was even better than the musical.
My picks are Dr. Zhivago, Fight Club and Shawshank Redemption. Oh and Godfather!