I just finished Cassandra Clare's followup trilogy to her Mortal Instruments series, The Infernal Devices. Like Mortal Instruments (the first of which, City of Bones, is about to be a movie), and a slew of other series geared toward teenage girls, it's quick and light reading, but Clare is an excellent writer, so she can weave a more believable, engaging tale than a lot of other authors I've encountered. It's worth mentioning that for me, The Infernal Devices was several lengths better than The Mortal Instruments. I think Clare honed her craft. ;)
Another good author pick might be Libba Bray, whose latest title, The Diviners, I just borrowed and am about to start. I was impressed by the first in a trilogy of hers, A Great and Terrible Beauty, even if the second two fell a little flat. I've heard The Diviners is another winner.
I thought I would include a list of books I've enjoyed, just in case you find yourself curious:
The Infernal Devices Trilogy -- Cassandra Clare
The Mortal Instruments Series -- Cassandra Clare
A Great and Terrible Beauty -- Libba Bray
The Unbecoming of Mara Dyer -- Michelle Hodkin
Harry Potter -- J.K. Rowling (obviously)
The Hunger Games -- Suzanne Collins
The Giver -- Lois Lowry
Weetzie Bat Series -- Francesca Lia Block
Hush, Hush -- Becca Fitzpatrick
Not to mention that big-time adult fiction authors such as James Patterson, John Grisham, Jodi Picoult and others are now trying their hand at young adult fiction and succeeding commercially.
The reason I love The Infernal Devices trilogy, for example, is that it puts the protagonist (usually a teenage girl in teen fiction) squarely in her place as heroine. She is depicted as intelligent, a little headstrong, and the type of girl who goes after what she wants, even if she's not totally sure what that is all the time. Of course, they're teenagers; they don't know what they want. This is what gives teen fiction that bit of an edge, in my opinion, when it's done well: the visceral, emotional, teenage response to everything creates conflict in itself. The theme or plot is usually a little less complex than adult fiction--that should go without saying. But where adult characters might try to sort things out logically, such as a middle-aged character looking back on past experiences which shape this new experience, teen characters don't have past experience to guide their decisions, so their responses to conflict are usually rash and immediate. And the basis for even more conflict. Authors who can really tap into the emotional whirlwind of teenage characters are the ones who can create really engaging fiction.
Summer reading at its best!
NPR.org has a great list of 100 Best-Ever Teen Novels, some classics and some recent titles. A good place to start!