-Scott Westerfeld.
-Francesca Lia Block and Melissa Marr (it's sci-fi/fantasy, but darker)
-Gemma Doyle Trilogy
Um...kind of hard to explain. Girls at an all girls school way back in the day can enter in a weird, other-wordly realm. Great ending. Amazing ending, actually.
-Guardians of Time Trilogy
People have powers and are able to travel back in time to create others from changing the past, if that makes since. Not amazing, but entertaining, and pretty sad, but great ending.
-The Book of Lost Things
Absolutely great. One of my favorites. If you like Pan's Labyrinth, you should read it. If you didn't like it, well, you should still read it.
-Narnia, of course. Genius books. (And C.S. Lewis was Tolkien's bff! Wild, huh?)
-A Wrinkle in Time.
It's a classic book, though not as popular as Narnia or LOTR. But it's in my top 5!
-White Oleander but something Fitch
Mind-numbingly amazing. Truly. It's about a girl who is thrown into foster care and deals with suicide, sexual abuse, starvation, and whatnot.
-Anything by Sarah Dessen, Deb Calleti, Maureen Johnson, Sonya Sones.
These are all authors that write young adult fiction about everyday girls and thier lives. Though they usually have romance, the girls deal with other stuff like being overweight, death, and real-life problems.
-Speak
A girl is raped and ostracized by her peers.
-How I Live Now
A girl is sent to her aunt's house over in the London-esqu area. Then things get wild. Incest is involved, and a war. (modern time!)
-Amazing Grace by Megan Shull
Girl gives up her celeb life, sneaks off to Alaska, makes great friends, while keeping her real identity a secret. (I know it sounds like Hannah Montana, but I promise, it's not!;) )
-Amelia Atwater-Rhodes Vampire Series
Great. Creative. Interesting. She wrote each book from a different character's point of view, so you get to see a ton of different perspectives. And she wrote them back in the 90s when she was only 14-18 but they're very mature and not like a teen wrote them.