What are some must-read novels for teen girls?

Some books I have read and LOVED are: "Memoirs of a Teenage Amnesiac", "Double Identity", "Real Mermaids Don't Wear Toe Rings", "Stealing Heaven"............and I really need some more titles....It doesn't have to be excatly similar to the ones I listed above, just anything you think a teen girl should definately read. I am open to everything (just not boyish scifi stuff :P)