Math Facts
Pumpkin Game
http://fun4thebrain.com/addition/pumpkinadd.html
Grand Prix
http://www.multiplication.com/flashgames/GrandPrix.htm
Bug Race
http://www.mathsonline.co.uk/nonmembers/gamesroom/bugs/bugrace3.html
Math Baseball
http://www.funbrain.com/math/
Fact Dash
http://www.mhschool.com/math/2003/student/index.html
The ArithmAttack
http://www.dep.anl.gov/aattack.htm
Murb Math Game
http://www.fun4thebrain.com/murb/murb.html

Subtraction Games
Fleebur and Spinky
http://www.fun4thebrain.com/subtraction/subfleebur.html
Murb Math Game
http://www.fun4thebrain.com/murb/murb.html

http://www.oswego.org/ocsd-web/games/SpeedGrid/Subtraction/urikasub1res.html

http://www.aplusmath.com/games/picture/SubPicture.html

http://www.oswego.org/ocsd-web/games/SumSense/sumsub.html

http://www.weeklyreader.com/kids/games/subtraction.asp

Math for Kids (many links to math sites/games)
http://kidsmath.about.com/mbody.htm?once=true&

Puzzles (puzzles in geometry, logic, math, weight)
http://www.freepuzzles.com