Paper Towns is the third John Green novel I've read, and my favorite so far. Although yet again, I spent the entire novel worrying that he'd kill someone off.
Quentin Jacobsen is in his final semester of high school and has spent nearly his entire life being in love with Margo Roth Spiegelman. Q (as his friends call him) and Margo were friends as small children, but she long ago traded him in for the popular clique and dating jocks. Yet for Q, and maybe even the entire school, while they all live their lives in black and white, Margo lives hers in color. The school is always abuzz with some rumor (that inevitably turns out to be true) about her crazed adventures.
A month before their high school graduation, Margo enlists Q for wild night to be her getaway driver while she exacts revenge against various friends and cheating boyfriends. And the next day, Margo vanishes. Q spends the next month trying to decipher all of the clues Margo seems to have left him, and plans to unravel the mystery and get the girl. Though on his quest, Q finds that he never really knew Margo at all.
As with previous John Green books, the main character's friends are hilarious and far more practical than the hero is. And the object of affection is fascinating and complex. I didn't care for Margo as much as Q does. But I do remember what it's like to be in high school and to be completely wrapped up in someone who seems to be so bold and colorful.
Edited to add: I was especially entertained by the fact that at the same age Q and his friends spend hours talking about Walt Whitman, my friends and I were trying to decipher Nirvana lyrics.