I'm very nostalgic for the NES games of old, especially the early ones, which were the first video games I ever played. Most of them I played at my friend's places or I borrowed them.
Trojan (my first gaming experience ever)
Super Mario Bros. Series
Mega Man Series
Batman
Teenage Mutant Hero Turtles
Fester's Quest
Maniac mansion (the NES version!)
...and my nostalgia game number 1 The Legend of Zelda (& Zelda II)
I beat most of the games numerous times, even if they were hard as hell (Mega Man I'm looking at you!). I guess I was a real pro gamer back then... Of course there are also the old PC DOS games, including countless adventure games, but those came about 3 years later.