Lord of the Flies, William Golding
Fantasy. The Lord of the Flies is a dark book about a bunch of British boys who crash a plane onto an uninhabited island in the Pacific, where they have to survive until help arrives- if it ever does. At first, everything seems to be going well. The boys have elected a leader, the quiet Ralph, who gets most of his ideas from his ever loyal friend Piggy (that's the nickname that the boys give him, because of his larger stature, and because of his clumsiness), and they get a huge fire going, as to alert passing ships of their presence.
In a few days things start heating up when the headstrong Jack (not me, I swear) starts to get jealous of Ralph's position and leaves the main group with his followers to go to the forest and live there, where they become something like wild beasts, losing self control and going savage. On top of all of that they have convinced the other boys to join them, leaving Ralph all alone with Piggy.
Things really get bad when Piggy gets killed by a falling boulder, and Jack and his followers start hunting for Ralph, who ran into the woods. Just as Ralph got surrounded a boat landed on the beach, saving the boys from turning into wild animals.
This is one of the most controversial books ever, because this book is about how mankind is so corrupt that even children can't go against it's destructive nature. A very deep and psychological book, I would recommend it for teens 13+