Quake I

[Velcrosasquatch]

I WANT TO PLAY QUAKE
The best overall way to play the game in my opinion is through Quakespasm:
Quakespasm[quakespasm.sourceforge.net]

BUT QUAKEWORLD
EZQuake[ezquake.sourceforge.net]
FTE Quakeworld[fte.triptohell.info]

BUT I WANT TO EYE CANDY/SOME POPULAR MOD DOESN'T WORK
Another controversial option is Darkplaces, it's generally ok but it's generally unfaithful.
Still as a whole, Darkplaces is still fairly popular.
Darkplaces[icculus.org]

Consider adding the line "sv_gameplayfix_droptofloorstartsolid 1" to your autoconfig when playing classic Quake in Darkplaces.

WHERE CAN I FIND OUT MORE ABOUT QUAKE I RELATED STUFF?
Quaddicted has tons of info, content, and is still maintained:
https://www.quaddicted.com/

QUAKE HAS MUSIC!?
Quake I and II both have soundtracks, but the Steam releases omit them.
Thankfully Google exists so you can find both of them

MY RUNES DISAPPEARED!?
open console and add "impulse 11" until you get all your runes back