Uglies - Scott Westerfeld

In Tally Youngblood's world, looks matter. At sixteen everyone undergoes a transformation from "Ugly" to "Pretty" and is catapulted into a high-tech paradise where the only thing that matters is having a great time and you never have to worry or think for yourself. Tally can't wait. But then, with just weeks to go to Tally's birthday, her friend Shay runs away and the ugly truth about the world of the Pretties starts to reveal itself. What if the beauty of the Pretties utopia really is just skin deep?