I think it was pong on some sytem i cant really recall well.
Then on some Apple system (i think) was some lame text adventure game.
Games i more fondly remember...
On PC it was Space Goose (played for hours & hours with my brother, think that was the 1st color game i played).
Doom & Doom2 are probably the games that (to this day still) had the biggest impact on me, playing them at night with the lights off - awesome. Must be the game/s i have spent the longest amount of hours playing. Downloaded & played literally hundreds upon hundereds of user made levels (.wads)