Games in classroom

I must admit that I am leary to make use of computer games in a classroom setting as a teaching aid.  While their are historical games that ca be used as a teaching aid, I would not recommend their use on a continuous base.  If games are to be used in the classroom, they must have a specific teaching need that they fill.  One of the only games that I can think of that fills that requirement is the Oregon Trail software.  That is the only computer game I can see using within a class period.  Any other games, like ones dealing with historical trivia, would only be used in the cases of per-test review.