Starfall http://www.starfall.com
Between the Lions http://pbskids.org/lions/
A+ Math http://www.aplusmath.com/
Fun Brain http://www.funbrain.com/
Funschool http://funschool.kaboose.com/
National Library of Virtual Manipulatives http://nlvm.usu.edu/en/nav/vlibrary.html
MIKIDS http://www.mikids.com/
Kindersite http://www.kindersite.org/Directory/DirectoryFrame.htm
Rainforest Math http://www.rainforestmaths.com/
Little Fingers http://www.little-g.com/shockwave/loading.html
Alphabet Practice http://www.playkidsgames.com/alphabetGames.htm
Roz's Math-a-rama http://www.eduplace.com/kids/hmm/