DOOM was the game. A first. Before that there was darkness and boredom.
Never liked Quake, it never had the edge.
I started seriously into computers because of DOOM. Serial cable (null modem) networking my 486 DX33 with 8Mb of RAM and a 1Mb graphics card to play coop (equal to a 2GHz +CPU with 2Gb RAM with a GF4 4600Ti these days).
Deathmatch only replaced coop because of the slow speed available to 'net games.
DOOM3 looks great. Will have wait to play. Hope the networking / gameplay is good as the lighting, graphics and sound look great.