I have no idea. I either started playing stuff on the C64 or the Atari but I can't remember. Asking this question is like asking "What TV show got you interested in TV?" I can't answer such a ludicrous question because I don't have memories that go back that far. Games just have always been there and you play games.

That said, I can't even remember the names of any Atari games my parents had and I can no longer remember C64 games either...except for kickman, Mario Bros (Not Super Mario...just Mario Bros.) and Montezumas Revenge(Awesome Game). These I know are not the first but they are awesome all the same.