http://www.galacticfleets.com/
This is an addictive free online space trading and combat MMORPG (massive multiplayer online role-playing game) that you can play in your browser. The game lets you control thousands of starships and explore a vast online galaxy, made up of over 160,000 solar systems.
http://www.playonlineforfree.com/
This site offers a good roundup of over 3,000 free online games, ranging from classics to cutting-edge titles. The site offers descriptions for each game, and visitors can rate each title as well. Categories include action, arcade, casino, Nintendo, puzzles, role-playing, sports, and more.
http://www.poparcade.net/
This site has a good collection of over 300 free online games. Categories include action, adventure, arcade, casino, puzzles, sports, strategy, and more. New games are added here weekly.
http://www.freeplaysolitaire.com
At this addictive site, you can play online solitaire games in your browser for free. Unlike most solitaire games, here you play against the clock for points. The faster you play, the higher your score.
http://www.play.vg/
Here, you'll find a fun collection of free classic arcade games that you can play in your browser. Categories include action, adventure, board games, Pac-Man, puzzles, shooters, word games, and more.
http://www.goodsol.com/online/
This site offers three free, fun online solitaire card games (Klondike, FreeCell and Spider) that you can play in your browser. The card games here feature nice graphics, as well as a nifty right-click move feature that makes moving the cards especially easy.
http://www.playnetrek.org/
This is a free multiplayer online space battle real-time strategy game. A classic title, Netrek has been around over 20 years, but is alive and well, thanks to a dedicated network of volunteer developers, and it remains as addictive as ever. (For Windows, Mac, and Linux).
http://www.chosenspace.com/
Looking for a challenge? Chosen Space is a fun, free Web-based massively multiplayer strategy game set in space. Here, you can become a bounty hunter, join a trading federation, control an empire, and much more. The game is turn-based and simple to play, but it takes time to master.
http://www.playf1.com/index.php
A free fantasy Formula One racing game that lets you create your own F1 team, consisting of drivers, engines and tires, and score points based on the results of the 19 races of the 2006 Formula One season.
http://www.wiredarcade.com/
This site has a fun selection of free games that you can play online. Game categories here include action, adventure, arcade, puzzles, shooting games, sports and strategy.
http://www.nobullgames.com/
Looking for fun? This regularly updated site offers over 1,000 free Flash and Shockwave games that you can play in your browser, with any operating system. There's also a nice selection of Windows-only DirectX games. Categories here include action, adventure, arcade, cards, puzzles, RPGs, sports, strategy, and more.
http://www.grumpventures.com/
An addictive, free online card game that is based on a solitaire layout (but also lets you compete against three other players). Grump features colorful graphics and nice sound. Note: this game requires the free Macromedia
http://goodwebgames.com/
Here, you'll find a fun collection of free online games in Java and Shockwave format. Game types here include arcade, action, classics, puzzles, racing, shooting games, slots and strategy.
http://www.impressivegames.com/
At this site, you'll find a nice selection of free, chat-enabled online games that you can play in your browser. Categories include action, adventure, puzzles, sports, and more.
http://www.gamecricket.com/
If you enjoy the game of cricket, this site is a must. Here, you can play a free online statistical simulation of a one-day cricket match. You can also use this site to predict the scores and results of one-day international cricket games.