Loved Doom, but preferred Quake. The latest iteration, Quake Live (now on Steam, cheap) is my favourite multiplayer online game.
I tried playing year or two ago but they 1) removed the original q3 audio assets (wtf?) And introduced auto-strafing...
Maybe people moved to Quake Champions? Quake live was a great game. Also is used to be browser based when it started!!
After Quake 3 came Quake 4, Enemy Territory: Quake wars, and Quake champions.