Five Flavors of Dumb by Antony John
There's so much going on here—a girl right front and center, a cheering crowd, a rock concert, a brick wall, a big title—and yet it all works together. Personally, I've never seen a concert incorporated into a book cover, so I think it's a really unique aspect to have. The color scheme is really great, too. Even little details like the pulled-back sticker that has the author's name on it really add to the cover.