Diana Wynne Jones books are good.  I would start with The Lives of Christopher Chant.

Megan Whalen Turner's series.  It starts with The Thief, then The Queen of Attolia and The King of Attolia.

I second any of Diana Wynne Jones' books!

She might also like the Artemis Fowl books (or other books by Eoin Colfer), Diane Duane's Young Wizards series, Susan Cooper's The Dark is Rising Sequence, The House with a Clock in Its Walls and/or The Letter, the Witch and the Ring by John Bellairs,  the Chronicles of Narnia, and A Wrinkle in Time by Madeline L'engle.

I enjoy Meg Cabot's books (the 'adult' ones) not sure what age she appeals to in the younger generation but I know she  has some like the princess diaries but I think some are a bit older..

I'm glad there are more books for this age now . When I was in high school there wasn't much available (I'm 40 now) and I was tired of reading 'kid' stuff and my mom wo uldnt' let me read the 'adult' stuff..

There's a series called "Fingerprints" by Melinda Metz which is sort of paranormal/mystery. It's about a girl who can read thoughts by touching their fingerprints left behind on lockers, books, etc. It's a 7 book series about her trying to find out how she got this power and what happened to her mother who died from a similar power. I LOVED this series at 16 and read the books over and over. I lent the books to all my friends and they sped through them too.

The person above me mentioned Meg Cabot, who I also liked at 14-16, but I preferred her mystery series like "The Mediator" series (there's 6 books in that one, though the first 4 are the best) and the "1-800-Where-R-U" series, which has 5 books (the 5th one is really bad though, in my opinion. The author wrote it years later b/c her fans begged for it and it was less mystery and more corny romance. But I'm 19 now so maybe the books no longer appeal to me.)

I'd also recommend the Narnia series... and Laurie Halse Anderson is a great writer. She wrote "Speak" which is darkly funny about a 14-year-old who has lost all her friends. A warning-- it's about rape, but I think the book is fabulous and even though people ban it for being "sexual" it is FAR from that and shows girls to speak up when someone has done something horrible to them. The rape is only mentioned in one scene, really, and not graphic, and it's more a book about the girl struggling to speak up and find her voice. It really captures the voice of teenagers, I think.

WOW THAT WAS LONG. I just had a ton of coffee and am going nutso!

The Lightening Thief (Percy Jackson and the Olympians series) by Rick Riordan

Sea of Monsters (Percy Jackson and the Olympians series) by: Rick Riordan

Inkheart & Inkspell by Cornelia Funke

Magyk by: Angie Sage(Septimus Heap Series)

Flyte by: Angie Sage(Septimus Heap Series)

Physik by: Angie Sage(Septimus Heap Series)

My daughter is 15 and she really enjoys the Left Behind kids books. There are a lot of books in the series but they are really good. I havent read them personally but she just loves them and wants more.

I books from Meg Cabot and Diana Wynne Jones on my shelf that sound perfect for your daughter. At that age, however, I gobbled up historical fiction by Ann Rinaldi-- I have two of her books on my shelf as well. Also The True Confessions of Charlotte Doyle is on my shelf, which I loved in eighth grade.

The Bartimaeus Trilogy by Jonathan Stroud

The Abhorsen Trilogy by Garth Nix

My husband and I just love these books!  Great YA fantasy fiction.

Robin McKinley's "Beauty" and "The Blue Sword"

Stephenie Meyer's "Twilight"

Jessica Day George's "Dragonslippers"

Scott Westerfeld's "Uglies" series

Libba Bray's "A Great and Terrible Beauty" series (for a little older teens, I think)

Twilight Trilogy by Stephenie Meyer

A YA series with vampires. I have read all three and LOVE them. I just found out they were YA!

#1 Twilight

#2 New Moon

#3 Eclipse.

They are all pretty long books. I think they are simillar to City of Bones.

My 14 yr old daughter loves the Stephanie Meyers Twilight trilogy, she has read them 3 times.  She also liked the Shadow children series by Haddix and Burned by Ellen Hopkins.

Dee

I second Libba Bray's series.  I've read the first two and loved them and now my oldest niece (13) is hooked.  She's waiting on me to give her the second book.
My niece also loves the Uglies series.

If she liked Harry Potter she may want to try the Septimus Heap series: "Magyk," "Physik" and "Flyte."  Also, I LOVE almost anything by Gail Carson Levine, "Ella Enchanted," "The Princesses of Bamarre," and "Fairest" are some of the best. Also, "Goose Girl" or "Princess Academy" by Shannon Hale are excellent.

The girls in my high school library are all into the "Twilight" series by Stephenie Meyer, and I can't keep the Ellen Hopkins books on the shelves, which include "Crank,"  "Burned,"  "Impulse,"  and "Glass."  They are written in verse, and really appeal to the teen girls.  While the subjects are controversial, (drugs, pregnancy, suicide, etc.), the girls tell me they have uplifting endings.   I am sure they are not for everyone....

My 16 year old daughter (who pretty much runs this account) recommends the Charlie Bone series by Jenny Nimmo. Garth Nix books like the "Keys to the Kingdom" series or "The Seventh Tower" series. I third Libba Bray's Gemma Doyle trilogy, and Scott Westerfeld's "Uglies" series. I seem to remember my daughter loveing the Remnants series by KA Applegate when she was 14. Hope this helps.

Tamora Pierce (all of them! she has a bunch of mini series)

Mercedes Lackey - the valdemar series. Her other books are a little more adult that those.

Fearless series (if she likes books that are fantasy, but based in modern day)

I <3 young adult books...even though i'm technically an adult now and no longer a YA

I'm sure she'll LOVE these books.

The Land of Elyon

The Last Apprentice

and maybe The Belgariad

I didn't read the whole thread so I don't know if anyone recommended the Left Behind series.  There is a kids series and an adult series and both would be excellent reading.  There are 40 of the kids books and 13 of the adult but there are also series branching off of the Left Behind series.  Such as the Soon series (Underground Zealots) and the military series and the Rising series.  They are all awesome and really keep your interest.  The kids series is about a group of 4 teenagers trying to make it through the tribulation.  VERY good series.

If anyone has books 29-40 I am desperately looking for them!

the Blue Blood Series(Vampires)~Melissa de La Cruz, revealers and univited (witches,vamps+ghosts) Amanda Marrone, the Great and Terrible Beauty series Libba Bray (my favorites) (Girl Power, other worlds and fantasies), Wake and Fade Lisa McMann (dreams), the Mediator series Meg Cabot (ghosts). They are all really good books i have all of them we could swap some or you can go but them but they are all just really great she will love them. O and of course a crowd fave The twilight saga i havent read any of those but heard they were good.