NASA Kids' Club

Games to support national education standards in STEM -- science, technology, engineering and mathematics.

http://www.nasa.gov/audience/forkids/kidsclub/flash/index.html#.U__V57xdUt1

Teach Your Monster to Read

A series of free games to practice the first stages of reading development.

http://www.teachyourmonstertoread.com/

PBSKids

A great place to find social studies, science, math, ABC, rhyming, teamwork, and creative games.

http://pbskids.org/games/all-topics/

ABCya!

A great website to practice math, letter identification and creativity.

http://www.abcya.com/

Starfall

Practice for reading, letter identification, and math. 

http://www.starfall.com/