Uglies by Scott Westerfeld
Faith5414
Tally is about to turn sixteen, and she can't wait. Not for her license- for turning pretty. In Tally's world, your sixteenth birthday brings an operation that turns for from a repellent ugly into a stunningly attractive pretty and catapults you into high-tech paradise where your only job is to have a really great time. In just a few weeks Tally will be there.
But Tally's new friend Shay isn't sure she wants to be pretty. She'd rather risk life on the outside. When Shay runs away, Tally learns about a whole new side of the pretty world-and it isn't very pretty. The  authorities offer Tally the worst choice she can imagine: find her friend and turn her in, or never turn pretty at all. The choice Tally makes will change her life forever.