Actually beating a game? Probably SMB on the NES? Before that you really couldn't beat games, you could just keep playing for the high score.
I think some older games had endings but I am hard pressed to remember any of them right off the top of my head.
As far as older games, playing Asteroids was pretty cool but no joystick... uuuggghh made it so hard, I mean I was already having to stand on a chair to play the thing damn it... Was so happy the newer games had joysticks and dials. (Loved Tempest, so fun!) Also <3 being tall enough to play games with no chair/stool needed!!! Growing up had its advantages!!! lol
I remember my older brother getting so mad at me... I can't help it I am a freak of nature and was better at video games at 4 than he was at 14... lol