Hilary Frank, I Can't Tell You and Better than Running at Night. The former features a college-age guy who has a falling-out with his friend and stops talking, communicates with notes. But that means he can't tell his friend that he's falling for her. He also has an awesome sense of humor (for example: hears an ad on the radio for a drawing for a bike and thinks, 'What would it do with it? Hang it in its spokes?'). The latter is also about college, but this time it's a girl in art school. She ponders about the importance of sex and the meaning of art.
Anything written by Francesca Lia Block. She is sooomade of awesome. and Nick and Nora's Infinite Playlist, which was cowitten by Rachel Cohn and Dave Levithan. They also cowrote Naomi and Ely's No Kiss List, also very excellent.