I did not read the book and absolutely loved the movie! Two people with me, who had read the book, still really liked the movie, but those who have not read the book will like it more because it is more fun to watch when you have no idea what is going to happen. It's an intense, gripping, puzzle that is fun to watch unfold.
9.75 out of 10. Attack of the Show on the G4 TV network thought Heath Ledger's Oscar talk was mostly because of his untimely death. After seeing the movie, I disagree with that thought process; he totally deserves the Oscar and it is so sad he won't be able to make more movies! My two companions at the show agree with all of the above as well.