It appears I'm not as old as Frink, but maybe I can take 2nd in this thread.
Riverraid, Pitfall 2, Defender, ET, Star Raiders, Prince of Persia, Loderunner, Donald Duck's Playground, Gertrude's Secrets, ZZT (ZZT-OOP was my first programming langauge!), Logowriter, Mario, Mario3, Batman NES 1987, METROID!!!!, Sonic, King's Quest, Monkey Island, Indiana Jones and the Last Crusade the Graphic Adventure, Mean Streets, Super Metroid, Super Mario World
More later!