All of these are Doom2 deathmatch demos.
These are not rated as single-player demos are --  I  will only post high quality demos here.
Categorized by map only -- they are in no particular order.
Big Thank You to all of the sites that these demos originated from.
Doom2 Iwad demos
Doom2 Pwad demos
 Bahdko -- the only complete Doom deathmatch site on the net.
 Doomed - Deathmatch Garrison -- fx
 Ugwad -- old school Doom demos.
 Yasuko -- 3 and 4 player deathmatch wads and demos
 Clan ZAP -- fx / MMX / Sedlo ...
 Clan Nightmare -- John / Adam / Adam / Slag / Pyth / Zamel / Radek
 Doomaniax -- X-Jack / Bolton / Jacih / Vito Lee  ...
 The Doomers -- Radek / Avenger ...
 Yeti -- outstanding deathmatch pwads with demos to match.
 CsDoom -- Client/Server Doom port
 The Doom Deathmatch Resource -- Tawney / Tarin
 Skulltag -- by far the best Mod deathmatch port/game.
 Captain Mellow -- one-stop bot shopping.
 Doom-CZ -- a Czech deathmatch site
 Dead Simple -- Lots of Zdoom dm demos.
 Brotherhood of Vengeance -- very small variety of Zokum demos.
 Opulent -- my deathmatch pages.