It really is a fantastic series, with the exception of the fourth book.. That one not so much. The original trilogy though, is fantastic. It's nothing like Gossip Girl at all.
They're about this uberly controlled society, and how the progtagonist deals with it. Until 16 you're an "ugly" and you live across the river away from all the Pretties. The Pretties are over 16, and have gone through surgery to be beautiful and perfect. They live a continuous party lifestyle until they're old, like 40 or so, when they become parents and take up jobs. You find out more about the pretties and the cities and what not, but I don't want to ruin the storyline.
In the first book (Uglies), Tally is an ugly who meets up with this girl, Shea, also an ugly. Shea wants to run away to this place called The Smoke, which is made up of a group of people who stay ugly forever, and work to live. It's a rough lifestyle, almost camping. So, the city sends Tally after Shea to betray the Smoke, where some stuff happens involving Tally and Shea and this kid, David. I'm trying not to ruin the plot, haha.
But it's a great series.
Umm, I'd try the early Maximum Ride books. They were less stupendous when the plot ended and Patterson's commentary on global warming started, around book four I think. (Not that there's anything wrong with politics or anything, but he turned the entire book series into it.)
Graceling and Fire, by Kristin Cashore were really good and kind of like the Hunger Games.
Also, Percy Jackson, on the off chance you haven't read that. Always a good series.
I've heard good things about Matched, but haven't read it. The Giver was good, and so were Blue and Messenger.. but I don't know what age those are aimed at.
I just read Hunger Games too! Three nights in a row, all three books, and I bought each one on kindle because I couldn't possibly wait for Barnes/la bibliotheque. It was a pretty dang good series and I tell everyone and their mom about it.
Have you ever read Feed? Or, Across the Universe? < that one just recently came out and I enjoyed it a lot. Utopian flair, mad dictator, that sort of thing. Feed is a bit different, but still a great read.
The Giver by Lois Lowry. It is a great story and it also happens in a futuristic controlled society. It is very similar to the Hunger Games in many aspects. I hope you like it. =)