I watched each of the three movies once and then read the book. I read it in a week, I seriously couldn't put it down, even though I knew most of what happens.

I have never seen a movie that is as good as the book it was based on. That was until the Godfather. I think I benefited from having the pictures of Pacino, Deniro, Brando, Duvall etc in my head when I read it. This gave a real face to the book, however It takes out that 'imagination' part of it.