Game Interventions provides onlinelearninggames for various school subjects.. Various subjects andlinksinclude:
Reading, phonics, decoding, spelling,
http://www.roomrecess.com/pages/ReadingGames.html
http://pbskids.org/games/reading/
http://www.knowledgeadventure.com/subject/reading-games/
Language
http://interactivesites.weebly.com/language-arts.html
http://www.sheppardsoftware.com/web_games_vocab.htm
http://mrnussbaum.com/langgames/
Math, multiplication, Add/Sub, etc
http://www.mathplayground.com/
http://www.e-learningforkids.org/math/
http://www.softschools.com/math/games/
Science
http://www.sciencekids.co.nz/gamesactivities.html
http://www.sheppardsoftware.com/science.htm
http://www.learninggamesforkids.com/
History/Social Studies
http://kids.usa.gov/play-games/history/
http://www.history.com/games/
http://www.learninggamesforkids.com/social_women_in_history.html
http://www.havefunwithhistory.com/activities/
http://www.sheppardsoftware.com/