Quake, if you value or respect FPS then you should know the ability to look around with a mouse or aiming with one... changed the scene of FPS instantly and every other game has followed suite. Also they made their own client for netplay, not LAN play. It spawned Robin Walker whom dev'd and brought out Team Fortress the mod. First mod ever and got hired by Gabe Newell at Valve to produce and work on pretty much everything. I attribute it all to Quake. Also the highest skill ceiling game ever made imo which is why it's not being made or pushed by Bethesda/Microsoft. They want stupid gamers who cannot setup their own servers or learn what latency is. Quake fixes this.