As one of the most influential First Person Shooters ever made, id Software's Quake is a definitive classic.
Taking influences from dark fantasy tropes, H.P. Lovecraft and science fiction, the story favours style over substance. A mysterious enemy code-named Quake opposes humanity, and the player is required to stop it with a copious amount of guns.
Quake was credited with popularising multiplayer deathmatches, and allowed players the ability to tailor each to their preferences. Abilities, item drops, and even gravity itself could be altered to create highly unique experiences. This was often to the point where the game became infamous for player-created sub-genres of online deathmatches. The same is true even of the single-player mode. The incredible speed players could move at promoted speedruns. The variety of weapons also pushed for more diverse combos of various weapons. Fragging someone with a rocket launcher so they are thrown into the sky, before riddling their airborne body with bullets, is just one notable tactic.
Many commonplace tactics were spawned from Quake's designs. Tactics taken for granted today such as rocket jumping or bunny hopping were popularised thanks to this game. In fact, id Software's intentional move to break away from realistic physics is what garnered it such a popular following. Even with the advances of technology, Quake can still stand up to the best First Person Shooters.