Curious George is a favorite of most kindergarteners. http://pbskids.org/curiousgeorge/games/roller_monkey/roller_monkey.html
This website has math, games, reading and a playground area. Much of its content is geared to pre- reading which is great for kindergarteners. http://www.funbrain.com/oddball/index.html
This BugOff game is good for using the direction arrows to move around the screen. http://kids.discovery.com/games/bugoff/bugoff.html
Typical Disney quality! A variety of activities and games on the site. http://disney.go.com/
Nice collectionsof activities for the computer. Good for review of many concepts presented throughout the kindergarten year. http://www.little-g.com/shockwave/games.html
Delightful selection of reinforcing activities for kindergarten age youngsters. http://pbskids.org/lions/games/