It's very unusual for me to watch a movie that's based on a book without reading the book first, but I'm glad I did with this one. I highly recommend The Boy in the Striped Pajamas to everyone - especially if you haven't read John Boyne's story. The ending will surprise you. Sorry that I can't tell you more but I don't want to give away the ending.
Plus, you get to see David Thewlis play a nazi - seriously, is there any role this man can't do?