The Atari 2600, the console that essentially kickstarted modern video gaming, remains the biggest step in the history of digital gaming, but also a platform on which several classic games were spawned and can still be enjoyed. Incidentally there's a lovely Atari 2600 collection you might be interested in being auctioned off at eBay.
The highest bidder will be getting a fully working console, 2 joysticks, a set of paddles, the power supply and 23 games (some of them boxed). The games include Yars' Revenge, Space Invaders, Demon Attack, Grand Prix, Defender, Atlantis (!), Mario Bros., Kaboom! and Centipede.
Seller ships to most places worldwide.