Realm667 for various items.
Agent Spork for some ROTT objects (Assuming he coded it.)
UnholyPimpin for some decorate stuff and some sounds
Mind Shear Software (In Pursuit of Greed) - For some sounds and sprites
Andrew Sega (a.k.a Necros) - Music (Most of which are slightly edited by me)
Vader - For the New HUD face, and the headless zombieman.
JoeyTD and Mike12 - Doomguy head rotation
CoTeCiO - HUD Graphics
Freedoom - Some graphics and sounds
Diodeus - Providing sprite rips from the game Eradicator
Twilight Frontier - For providing some sprites
Joel Huenink - Providing some sprites (The WAD "All Hell is Breaking Loose")
Anthony Galica and team - Providing some sprites and sounds (The WAD "Beyond Doom: The Apocalypse TC (an unfinished TC)")
Insomniac Games for the GoingCritical sound (Spyro the dragon, the very first one)
deathz0r - For the giant imp sounds (I got lazy, so I borrowed his sounds :P)
hacx for some sounds
DonaldDuck (zdoom forums) for the fist sprite.
Roland La Goy - For some neat sounds
agaures - for the zandronum helmet sprites
arch - revenants with hook hands.
mazmon - player sprite edits
Happy time circus 2 - cyberdemon head projectiles
vader - decybered mancubus (for megamind)