Armor Battle, The Electronic Company: Math Fun, and Las Vegas Poker & Blackjack which released 1979 for Intellivision.
I'm looking in to getting some 2600 games now since I have the Intellivision System Changer (an adaptor which allows Atari VCS/2600 games to be played on the Intellivision) to possibly get some titles older than that in my collection. Either way, it's pretty cool having games in my collection released in 5 different decades all still accessible and ready to play!