A Clockwork Orange.
Nah, not really, but the 21st chapter would have been good to complete the story rather than leaving it open. It was a good enough ending but somewhat lacking in my opinion.
I agree with the Golden Compass hate. That movie was terrible, absolutely fucking terrible and I'm glad that they aren't making a sequel as the Subtle Knife is my favourite in the series.
And pretty much every comic book ever made. Watchmen wasn't bad although most of that is because the book is really, really good and a pretty decent musical score. V for Vendetta wasn't too bad either, although compared to the book woeful. The Dark Knight was good but also had some big flaws and the first two Spider man movies were quite good. All other comic book adaptations have generally been bad movies, I haven't seen every single one of them, but many that I have seen tend to suck pretty hard.
EDIT: Dune, holy shit Dune! The book was great but the movie... well it wasn't bad exactly but that's because it's based on a really good book. It managed to capture the attitude, atmosphere and all that but the acting was wooden and the story was as rushed as all hell. Better actors, get rid of that yellow-grey tinge the movie had and spread it over three movies and you might have had something good going on.