I saw that Jessica cast the characters of the books she would want to see on the big screen, and I really wanted to borrow that idea, but I'm having such a hard time picking actors and actresses that would do my favorite characters justice. Kudos to you, Jessica, for picking such awesome people in your post! And, I realized there were several movies based on books that I wanted to mention in this post, so I jumped between a few different related topics. I hope you don't mind!
First, in answer to Jessica's actual prompt, I wanted to talk about one series that I'm very surprised hasn't been adapted for the big screen yet: Uglies. I think the story would do very well at the box office, especially considering what a huge hit The Hunger Games has been. I already compared the two series in this post, but I think Uglies, Pretties and Specials would make fun films. We can just leave Extras out; it's a weird fourth book that never should have existed, in my humble opinion.
Regarding books that have already been turned into movies, there are actually a few films that I think turned out better than the book. (I know, that's bibliophile blasphemy! Stone me now.) Most notably, I recall Atonement (which I explained here) and The Notebook (the movie added a lot more scenes of Noah and Allie's young relationship, which I liked better than their affair).
Usually, I can still enjoy movies based on books even when they aren't as good as the novel, because I understand the film can't fit all the intricacies of the novel (e.g. The Other Boleyn Girl, The Time Traveler's Wife and the Harry Potter films). When I don't like the actors/actresses, however, it makes it very difficult for me to enjoy the movie. For example, I still haven't seen My Sister's Keeper, even though Jodi Picoult is my very favorite author of all time, because I just cannot picture Cameron Diaz as the mom, and I don't even want to see her try. (Anyone who has seen the movie: Am I justified in not watching it? Or should I give it a chance?)
What are your thoughts on books turned to movies? Do you typically read the book before you see the movie? (I always try to!!)