Designed by David Crane for Activision, Pitfall was one of the Atari 2600's finest hours. You must guide Pitfall harry across deadly pits, past crocodiles, jump scorpians, and collect treasure.
It was the game to have for the 2600.
There was also a sequel, Pitfall II: The Lost Caverns, which surpassed anything else ever done on the 2600, bar none. You would swear that you were playing a nintendo, seriously.