Who said playing games had to take a bite out of your wallet? There are a number of web arcades that support free browser games, and while you aren't going to find Call of Duty: World at War or Left 4 Dead in browser form, there are some pretty good time-wasters out there.
Instant Action is the next step in web browser games. Using a browser add-on, Instant Action is able to deliver crisp 3D graphics and the type of game play usually reserved to full launch games. While still in beta, they do have a few fun games available. Expanding the web arcade and the way free browser games are played, it's definitely worth checking out and keeping an eye on in the future.
Kongregate has been called the YouTube of gaming. Not only is it a good web arcade, but it also focuses on "social gaming" by allowing you to rate the game. Kongregate also encourages independent developers to get into the action by uploading their Flash and Shockwave browser games for a share in the ad revenue.
One of many flash-based web arcades, Ninja Kiwi hosts a multitude of free browser games. It has an easy-to-use interface, and the games are ad-supported, so expect to see occasional advertisements while the game is loading. While there are many flash-based web arcades, Ninja Kiwi makes the list because the site is cleaner and less "busy" than most.
If you like pinball games, Pinbrawl might be the website for you. It features three different pinball games and you can compete against others for the top score of the day or the best score of all time. Pinbrawl uses Shockwave, so if you don't have it yet, the website might direct you to install it from the Macromedia site.
An "oldie but a goody," Netives has a number of fun Flash games like Marbledrop and Spider Solitaire and Mahjongg. If puzzle-based games are how you like to spend your idle moments, Netives is a great web arcade to bookmark.

A web arcade can be great if you are just trying to kill some time at work or need something to do while you drink your morning coffee, but if you want something a bit more involved, here are a few free browser games that are among the best:
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