This is a hard question for me to answer because my memory is so fuzzy on exactly what I got first. I played a lot of my cousin’s systems before I got my own, but my earliest systems were the NES and the Atari 7800. On the NES I played loads of Super Mario Bros. and Adventure Island - on the Atari 7800 I played Frogger, Defender and Pole Position II.
It was either Combat or Space Invaders for the Atari 2600. I think my grandmother bought both the 2600 and S.I. at once, and I’m not sure which game I played first. Combat was probably played first, though.
The fact that we even need to have a conversation about game preservation is just, like, the most pathetic thing ever. In a good world, it would be a no-brainer proposition. Of course the history of video games, and specifically the games involved, should be enshrined and preserved and presented in a clear and sensible fashion. Of course. And yet, here we are.