The fine folks at Machinima put together this list of Game Changing video games of the 1980s. It's a pretty good list. I can think of a couple games I would add to it, Adventure or Zork probably deserve to go on there, maybe Metroid. Also the first Madden game came out in 1989 I think so I'd put that in the running.
I just now realized after watching this how little clothes Princess Daphne wore. I doubt that was an accident, I'm sure there was a whole slew of kids that thought if they just kept feeding the game quarters they'd get to see some boob. I know that's what I would have done but I think I only saw Dragon's Lair in the wild once. It was an expensive game because it ran off laser disc, I think I saw the price and noped my way on over to Gauntlet or something.