Three of them. Pac-man on Atari: I remember watching my dad destroy this game. Score-wise, not physically. Altered beast on sega genesis: the graphics blew my mind. Goldeneye on N64: specifically the multiplayer. I remember thinking that this one was a game-changer. The difference between good and great players was absolute domination. The developer had created an environment where playing well had a certain finesse to it.