Uglies by Scott Westerfield
Ok, this book has to be one of the best sci-fi books I have ever read! It is all about this town in the future where when you turn 16 you undergo an operation to make you pretty. Everyone is separated into age/beauty groups, such as Uglies, Littlies, and Pretties. The main character of this book is an about to turn 16 year-old girl named Tally.
Tally wants more than anything to become pretty, just like her friend Peris. When Peris becomes a pretty, Tally finds a new friend named Shay. Shay and Tally share the same birthday and Tally excited that they are going to become pretty together. There is just one problem; Shay does not want to be pretty.
Shay wants to live Uglyville (where they live) and go off into the world. A world where people, gasp, do not become pretty!!! She tries to convince Tally to come along, but she refuses. Shay runs away on her own, but Tally must follow after her. You see, Tally will not be made pretty until she lead the awful Special Circumstances Pretties to Shay's secret location.
I won't tell you what Tally does, but I highly recommend this book. I can't wait to read the two sequels: Pretties, and Specials.