The Ender Series by Orson Scott Card
A great sci-fi series, and one of the best series I've ever read. It deals a lot with a futuristic battle school and takes place around Ender, the main character who has a knack for winning games.
Wheel of Time Series by Robert Jordan
A longer series, but very good nonetheless. Complex details and plots intertwine with the three main characters who all affect the overall fate of the whole world. Satisfying read, especially if you normally don't read long books!
