Me and Earl and the Dying Girl by Jesse Andrews in two days!
What makes it so awesome?
1. Our narrator, Greg, a senior in high school, behaves the way a real person would, teenager or no. I LOVE THAT. Upon hearing that his sort-of ex-girlfriend from middle school has leukemia, and that his mother wants him to reach out to her, here's how he reacts: "Urgh!"
Mostly, he's inconvenienced by Rachel's imminent demise, claiming several times that it, and their forced friendship, has "ruined" his life. This is how people think. As a result, I wasn't thrown out of the story by a perfect protagonist, yet Greg remains sympathetic because he genuinely tries to keep Rachel's spirits up by going over to her house every day and making her laugh.
2. Different scenes are presented in different formats, such as screenplay style, bullet points, or outlines. Besides being hilarious, it keeps information brisk and entertaining. Even descriptions of the movies Greg and Earl make are written like quick film reviews, with star ratings at the end.
3. The whole book is funny as hell. My favorite part is when (minor spoiler alert or whatever) normally straitlaced Greg and (less straitlaced) Earl accidentally get high after drinking their favorite teacher's mysterious soup. HAAAA! And then they can't decipher a text message, and it cracked me up like crazy.
4. Greg regularly breaks the fourth wall, referencing the fact that we're reading something "he" wrote, and how awful the book is, and how it may cause us to "want to do a homicide."
If you're looking for a YA book that works on about a thousand levels, add Earl to your list.