Mr Bee's Adventure: Has different levels
Hot Dog
Sliding Puzzle: Very small on the screen
Kinderweb's Childrens Games: Has a Shape game, an animal game, and a colour game, uses sounds!
PBS kids
BBC school: Numeracy games, different levels
Sonar Challenge by Double You: keep a ball in the air for as long as possible. Uses the mouse only. Difficult. (Japanese sounds)
Cyberkids
Ladybird: Fun & Games
Kids domain: Online Games
Aj Kids: All sorts of questions
Yahoo! Mazes
Yahoo! Word puzzles
Totally spies
Fox TV
Cartoon Network games (US)
Pacman (DK) (sounds)
Wanadoo online games (FR)
Lulu's Games
BBC Games
Tweenies
Thomas the Tank Engine
Etch a Sketch
GusTown
Kiddie Circle
Sheep Game
Games Centre (AU)
Playtime for kids Many different games
Kidtastic The City Games (uses sounds)
Wicked 4 kids Mr Potato head
Arcade games
BBC Sport Academy Games (many different games)
Hostedstuff -- click on Slime Soccer
Mini clip (try the Monkey lander :)
Roby Baggio Magical Kicks
EA Games
World Cup Soccer
Cartoon Network (UK)
The Official Harry Potter site (UK)
Disney site (US)
The Official Bob the Builder Website
Robotwars
Disney site (UK)
Fox Kids
Shrek website
Ultimate RCT