Battletoads & Double Dragon
Contra
Donkey Kong Country (1, 2 & 3)
Sonic (2 & 3)
Mario Kart
Super Mario World
Yoshi's Island (not sure if this is two player or not)
Street Fighter
Mortal Kombat

I dunno... I remember playing so many games for NES, SNES and Megadrive with my friend when we were little but I can't seem to remember names of any of the games, just what they look like and how they play.