You Tell Me: Best and Worst Books into Movies

I’m out-of-pocket this weekend, being in a wedding, so I’ll just leave this question for the comments:

Having taken our first steps into the Hobbit and Hunger Games movies, Great Gatsby just out, Ender’s Game coming soon and The Book Thief still being cast, what are your thoughts? What movies did you think captured their books well? What movies totally ruined the books? What movies might have improved the books?