Uglies: Uglies Quartet, Book 1 (by Scott Westerfeld)

Tally has grown up in a post-apocalyptic world where, at the age of 16, everyone is given an operation that makes their faces and bodies perfect. Before the operation they are known as "uglies," and after as "pretties." After the operation they live in New Pretty Town, enjoying a life of constant partying and pleasure. Tally can't wait.

Shortly before her 16th birthday she befriends Shay, who tells her about the Smoke, a secret community of those who refuse the operation. When Shay runs away to join the Smoke, Tally is given a choice by the Specials, the secret police: help them find the Smoke and betray her friend, or remain an ugly forever.

Author Scott Westerfeld manages a delicate balancing act in UGLIES. It's obvious that he had a point to make when he decided to write a book about a futuristic society that celebrates beauty above all else -- and that the world of the book is a not-so-logical extension of certain trends in today's society having to do with physical attractiveness, plastic surgery, mindless consumerism and pleasure-seeking, and divorce from nature. But he never hits the reader over the head with a message and, in fact, allows the lives of the pretties enough appeal to make the argument two-sided.

This intellectual argument is set inside a crackling, though at times maddeningly predictable, story. About two-thirds of the way through the book is a series of events that alert readers will not only have seen coming a hundred pages earlier, but they'll be frustrated that Tally so stupidly falls into them. But the final third is a breathtaking race to the cliffhanger ending.