Educational Computer Games

The title poses the question. I run a computer lab and need some new educational computer games for my students. They must be free. They are puzzles, word games, words, mathematical puzzles, construction toys (like Civilization), etc. I prefer websites, but they can also be too many programs. My students are bored with what I have on my computer, so if anyone can list a few and where to get them, I'd be very happy. Thank you.

Oooh FunBrain.com PBSKids.com and has a ton of good games for the younger. Scholastic and Discovery Channel are also excellent sites. My absolute favorite (and my children too) is Gamequarium.com. The site has a ton of different subjects and levels of difficulty is quite fun for adults too.

Enjoy! :)