Ender's Game
This movie was already spoiled for me because I read the book many years ago. But the movie can't help but spoil itself. It's a great film and one of the best adaptations of a novel to ever appear onscreen, but if you really know nothing about Ender's Game, and can read at a 9th grade level, honestly go read the book first. If you have time.
The problem is that by the time of Ender's "final exam," it's hard to imagine anyone in the audience sympathizing with Ender's shock that he hasn't really been playing a video game; he and his tween friends have been controlling actual spaceships…