On the plane on the way home from the LA SCBWI conference, I read Looking for Alaska. I laughed a little, cried a lot. I found the central event in the story to be the thing that was the "edgiest" about it -- the drinking and smoking certainly weren't glamorized, and the blow job scene was great for comic relief, and necessary for some parts of the story development, but it was described fairly tamely, really.
John Green's willingness to really go there, to the depths of the emotions that are associated with the event in the middle of the book and its ramifications, impressed me no end. His characters were realistically rendered, the events are all things that occur in the lives of teens, and his willingness to contemplate big questions of faith and death and afterlife and forgiveness make this a book that follows you around even after you've put it down.
Kids may pick it up and pass it around for the blow job scene, but if they read it, they'll come away with little gratification on that count, but lots of good messages about life.