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.
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.