Uglies is the first book in a very popular series of Young Adult dystopian science fiction, targeted primarily at teenage girls. It has spent over 50 weeks on the New York Times bestseller list (although it has since fallen off), and has been translated into 27 languages; it was first published in 2005, and it is still selling well. The originally planned trilogy has been expanded to a fourth book, and yes, a movie is in the works.
The basic premise is simple and familiar; in the future, everything is perfect -- and perfectly planned out. Goods are provided free-of-charge, no one is hungry or lacking for medical attention, and the government takes care of everyone. Once children are old enough to leave their parents, they are moved into dormitories; once they are 18 they are moved into the city, where they party all night (and eventually learn a trade); when they age out of partying, they are moved to the suburbs where they can raise a child if they wish; when they are old and ready to retire, there is a community for that, too. It is a good, well-planned, and safe life.
The primary hook of the story is that each of these changes in life-status is accompanied by a major operation - emphasis on major. The transition from teenager to adult is marked by an operation to change a person's natural form into a 'Pretty'. The bones of a person's face are scraped and built up to meet the scientific ideal of beauty; if a person is too short, their legs are lengthened, and if too tall they are shortened. Their body fat content is adjusted, and, of course, they get a complete makeover from eye-color to a new set of teeth.
The protagonist of the story is a young lady on the verge of becoming a Pretty - an Ugly. Tally Youngblood is feeling lonely, being one of the last in her year to turn 18 and undergo the operation to become a Pretty and move to New Pretty Town. She is especially missing her friend Peris, who changed recently and failed to keep his promise to keep in touch... Not entirely a surprise, as Pretties tend to forget the Uglies as soon as they leave Uglyville, but he had been her best friend for years, and he had promised. So she decides to sneak into his dorm to see him.
While adventuring in New Pretty Town, she comes across another Ugly - another rebel, a girl named Shay. Shay had not only found a way to sneak into the city, but also found a way to trick the hoverboards into riding along the river and through the woods to the ruins of the old city, abandoned hundreds of years ago. And in the ruins, there are also strange people - people who don't live in a city, and don't turn Pretty.
Tally is quite certain that they are crazy; how could anyone not want to be Pretty? And even if you didn't want it personally, there are important social reasons for turning Pretty; it eliminates negative feelings about body image, it reduces social competition, and it grants perfect health. Staying Ugly is not just weird, it's downright antisocial. So antisocial, in fact, that the operation isn't really voluntary. If you didn't want the operation, you would hypothetically have to run away... And Shay doesn't want the operation.
I wont tell you any more, except to say that the plot is very predictable, in broad terms. This is not to say that the story is boring; it has very strong themes of self-identity, and particularly how your identity changes as you enter adulthood. The characters are obsessed with body image, and also whether or not being obsessed with body image is a good thing. The major changes in personality as one enters adulthood are also an important aspect of the story. Being a highly structured futuristic society, the themes of personal freedoms and individuality are a given, and as this is written for teenage girls, there is of course some romance involved. This all makes for a rich mix, which I tend to think is a good thing in YA literature.
I have to admit, I do not think that this book is as well-written or as gripping as some of the popular books out now -- The Hunger Games and The Host would be higher on my recommended reading list, and even the Twilight books are more gripping. However, Uglies is quite engaging, and becomes more so towards the end, to the point where I have no doubt that I will be reading the rest of the series. I find it very much akin to Matched in tone and pacing.
Science fiction fans may have noticed that the story sounds quite a lot like an old Twilight Zone episode, Number 12 Looks Just Like You; Scott Westerfeld admits that he saw this episode when he was young, and that this influenced him. This is by no means a bad thing, as the idea deserves a longer treatment, and Scott Westerfeld does a great job of updating and filling out the idea.
The next book in the series is Pretties.