Seems most people confuse "landmark" with "favourite" or "original".
I'll agree with Civilization, and add Elite, Will Crowther and Don Woods' original Adventure, Bruce and Roger Carver's Leaderboard, Wolfenstein 3D ahead of DOOM, Melbourne House's The Way of the Exploding Fist, and whatever the first wireframe 3D flight sim was called.
(plus a few others I can't think of right now) :-D
