How They Croaked: The Awful Ends of the Awfully Famous. This is probably the grossest book I've ever read, which is the ultimate compliment for adolescent readers.
Detailing the deaths of nineteen historical figures, Georgia Bragg has done meticulous research and added so many tidbits and facts that readers will spend hours gleefully sharing disgusting information. Kevin O'Malley's illustrations add a touch of humor and lighten the mood of the gruesome deaths.
My students are learning about the Tudor Dynasty, so the sections on Henry VIII and Elizabeth I were among my favorites. In addition to detailing his death (um, did you know his corpse exploded in its coffin?), it has a chart of King Henry's unlucky wives, as well as the amount of food eaten in one day by Henry and his court (including 15 swans and 3,000 pears), and things that weigh as much as Henry VIII (58,060 U.S. pennies). This is exactly the kind of information I want to know about historical figures.
I will be recommending this book widely in order to convince young readers that nonfiction books don't have to be boring.