SimCity is an example I use to explain how a game can be put to educational purposes. For example, with newer versions (SimCity4), you can manipulate aspects of a community such as the commitment to education (city college vs. university, public vs. private schools, library) and explore consequences.
Some may have difficulty conceptualizing the game or how questions related to city management, infrastructure, etc. might be explored. I recently learned that Electronic Arts has made a free online version of the original available (SimCity Classic). You must access this from a Windows machine (ActiveX I guess) and you do have to register, but you might find this a useful way to explore some of the basics of a complex, interactive simulation game.
