Settlers of Canaan
Great for religion class, goes from Joshua to David. This could be a touchy game for a public school class as the game is very Christian-oriented. Otherwise, this is Settlers of Catan.
Call of Cthulhu
This is a role-playing game and free-form. It explores the horror mythos of H.P. Lovecraft which inspired Stephen King and other writers. References to Cthulhu are quite frequent, including Arkham Asylum in the Batman cartoon series.