44. Ender's Shadow, by Orson Scott Card.

Ender's Shadow is a parallel book to Ender's Game, dealing with his friend Bean's life before and at the Battle School. Bean grows up on the streets of Rotterdam, starving until he convinces a street crew how they can all get into the charity kitchens, found by a wandering nun, and tested for aptitude. Then he travels to the Battle School, and is faced with a new set of only slightly less terminal problems.

I liked this book just as much as I liked Ender's Game - more in some ways, because Bean is as extraordinary as Ender, but knows he also has to fit in with the rest. Some of the plot points seem a teensy bit contrived, but overall it was a really enjoyable read, and it fills out a little more of the story. It's written with the intention that you don't need to read Ender's Game to understand it though, and the author pulled that off really well. Both novels work well together, but are complete alone, too.