One title on the list:
Ender's Game (by Orson Scott Card)Read about the other titles on the list.
This one caught us totally off guard the first time we read it. Ender's in Battle School training to fight the Buggers for most of the book. After he gets promoted to Command School, Ender starts a new set of training simulations to test his ability to lead fleets in war. During his final simulation, Ender sacrifices an entire fleet to defeat the enemy and destroy the alien homeworld. He thinks he'll be expelled for breaking the rules of the game, but it turns out that no one cares. In fact, his teachers are all celebrating his victory because it was not really a simulation. Ender was really commanding an army, and he really committed xenocide.
See Orson Scott Card's list of five science fiction books sure to hook new readers.