Emulators: The Emulation Zone is a must see for old and young. Re-live classic gaming action on your nice new PC. Yes using these links you can be playing classics written for the VIC-20, Atari 2600, C64 and old school Arcade. Luverly Jubbly.
MAME is still king of the emulators, Multiple Arcade Machine Emulator, this is the official MAME page. This truly amazing program emulates hundreds of arcade games of yesteryear. Moon Buggy anyone?
Stella is probably the best Atari 2600 emulator out there, being free and running an a wide variety of systems. We run on Windows 98 without any trouble. A fantastic resource on the 2600 and history of games.
Classic Gaming is the best resource in the world for old video games. It's packed with news, features and links for almost every game and platform ever produced. It also houses the Vault, packed with emulators and ROMS, including Atari 2600