Online Game Sites

4kids - New find for me, have not checked it out well yet
Pogo - tons of games and you can win prizes too!
I Win - tons of games and cash prizes available
I Won
MSN Games - Tons of game, requires a small download to play certain games
Heavy Games – TONS of free web games!
Free Game Heaven - Play the best free games online!
ArcadeTown.com - Tons of free online games plus video games
Arcade Nut - FREE flash and java games to play online. FUN for all ages!
Sportsbook- Premier Online Sportsbook and Casino
Smashing Games -A good source for free flash games, added daily!
Free online games link -Free online games directory, freeware, roms, emulations, but also previews, cheats, reviews and multiplayer video games links.
Aard 3d puzzles- Addictive games with cool 3D graphics
Another directory-- This directory lists dozens of high quality free multiplayer online games, and includes a description and screenshot of each.
Online Game Library - A great selection of online games of all types, although not all are free.
Arghhh.net - Many  Java and Shockwave games by a small design team.
Yo Games- Directory of games
Freegameslotto- Play online scratch, games to win prizes
Noodan Free Games-  Hundreds of free games to download and play
Martial Combat- Fantasy Martial Arts game set somewhere between the classic martial arts movies and the world as we know it today. There aren't any special power blasts or superhuman strength, just good, old fashioned nonstop fist in your face action. 
Computer Games Online -A very comprehensive and useful guide to games. Frequently updated.
Cybertrek - The world’s first adventure game that requires you to know how to use your computer! You could win $500 ... if you make it all the way through the seven episodes.
Gameworldx- Exciting listing of hundreds of games
StarDart -A fun game set in the distant future, where faction leaders vie for control of the galaxy and the legendary Star Darts
The Do-It-Yourself Adventure- A text adventure that you help write as you play. Very fun.