Before I Fall
Before I Fall, by Lauren Oliver
Samantha is one of the most popular girls in school, the girl everyone envies who can get away with anything. But then she gets killed in a car wreck--and wakes up on the morning of the same day. Sam keeps reliving her last day, until she can figure out what she needs to do.
The interesting thing about the story is that Samantha is really a pretty awful person--she's utterly thoughtless. As she starts to look around her for the first time, she realizes that she has never seen the people around her for who they are. She has never understood that she has choices, and that what she does every day has consequences. It's not that she's been intentionally evil, but she has never once stopped to think about anything. Watching her learn to make choices and care about people was the element I liked.
The story is a bit long but very readable. It's been making a big splash in the YA world, and you could give it to your teen (though I'd say 14+).