I adored both Harry Potter and Twilight, and also this series, so maybe you'll like it, too. The first one is called "Uglies" and is about, well, it's hard to explain. Here's a summary from the author himself:
"Uglies is the first book of the trilogy. The second book is Pretties and the third is Specials. It's about a world in which everyone has an operation when they turn sixteen, making them supermodel beautiful. Big eyes, full lips, no one fat or skinny. This seems like a good thing, but it's not. Especially if you're one of the uglies, a bunch of radical teens who've decided they want to keep their own faces. (How anti-social of them.)"
Also, there is a fourth one called "Extras", sort of a epilogue, after all of the events in the first three books.
Scott Westerfeld has also written other series that I enjoyed, including "Peeps", and "The Midnighters". Check them out. =)