Uglies by Scott Westerfeld

This is an out of this world story that portrays a sort of future earth where everyone is surgically altered to be "pretty" when they turn 16 to reduce war and make everyone equal. However, the main character, Tally, changes her mind about this procedure after meeting a girl who says their is a surviving band of uglies who are living off the land like no one has done for thousands of years. She embarks on a journey to follow her friend and find this village and along the way she discovers many unsettling and scary secrets about her society.