Magnum PI, season 4, episode 3 "Smaller Than Life" has an Atari 400 with the expanded keyboard. A kid plays Defender and Missile Command, then uses his modem to connect to the FBI website to look up names. Classic.
One of the Season One episodes of Knight Rider involves a video game company, and KITT is shown playing a game on one of his monitors. I'm almost positive it was Intellivision footage, but I'd have to look at it again to be sure.