This series is absolutely one of the best SciFi BOOK series out there! Hands down!
Ender's Game book is awesome. However, the next one in the series, "The Speaker for the Dead" is absolutely a masterpiece. It literally changed my world-view in some aspects, and I can't say that very often.
That being said, I will definitely have to see the movie one day. I hope they didn't butcher it too bad cuz I will be pissed.