Uglies by Scott Westerfeld (2005, Paperback)

In a Utopian society where everyone, well almost everyone, turns beautiful on thier sixteenth birthday Tally sets off on an adventure to find a runaway "ugly" friend so that she can have the operation to turn her "pretty". In this society beauty reigns and everyone is made to feel "ugly" even though by the "Rusties" (us) society they would be normal. This fact is carefully hidden from the "uglies" who can't wait til their sixteenth birthday. However a few hundred people chose to remain ugly and every year a few more people join them rather than going through the operation to make them pretty. The book is all about Tally's adventures to find Smoke, a hidden society of "misfits", and her inner journey to discovering beauty isn't just skin deep. Sent as a spy to discover this secret society Tally finds beauty is not all it's cracked up to be and decides not to activate the pendant given to her be the "Specials", who are a cruel beauty, or does she? Although this is a teen novel I think any adult would enjoy reading it too.