While Quake is a major step technologically I never liked the mushy textures of the game. I am enjoying (to this day actually) much more the recogniozable settings and the refined gameplay of Duke Nukem 3D, with great level design. So this gets my vote.
https://www.youtube.com/watch?v=cRF-B_f-VZc
Shoutout to Chaos Overlords, a pretty good turn based strategy game with you overtaking a city. It is from New World Computing, which manifested as a pinnacle in strategy games, including making Heroes of Might and Magic 3 later, which I love.
https://www.youtube.com/watch?v=Vnwzkel6v8Q