This website has a lot of media/entertainment type things as well... but there are a host of "games" for geography, literature, science (yay science!), history, language, and sports. (I've spent a lot of time trying to get my best time of naming all 50 states.)
It’s Not the Tool, It’s How You Use It Mary Beth Hertz Instructional Technology Specialist Philadelphia, PA Diana Laufenberg’s History classroom at the Science Leadership Academy in Philadelphia Best practices for integrating technology in the classroom