The Doom Alphabet Game

[Kotzugi]

Bloodfalls

[Blue Shadow]

Chocolate Doom

[savagegrant]

Doom Honorific Title

[Doominator2]

E1M1

[Infirnex]

Flashlight

[Average]

Gibs.

[NuMetalManiak]

Hectic (Doom 64)

[joe-ilya]

Invurnul ability

[Guest]

Joe Pallai

[Gez]

Kotzugii

[joe-ilya]

Linear levels

[Zed]

MBF (Marine's Best Friend)

[joe-ilya]

Nuclear plant (E1M2)

[scifista42]

Gez said:

Kotzugii

:)

OBLIGE

[Acid]

(from the OP's list)

PWAD

[nicolas monti]

Quarantine (d2twid map08)

[YieldBitch]

Risen3D

[glenzinho]

Spectre

[CorSair]

TC (Total Conversion)

[joe-ilya]

Unto the cruel (E4M8)

[Springy]

Vae Victus (Wad series by Ditto head).

[joe-ilya]

Water

[Acid]

That is too broad. Like alot of the other words you mention.

XWadEd

[Avoozl]

Yesterday's Nightmare

[Springy]

Think that was mentioned Avoozl, could always have Yesterday's Brownies which is an old DM level.

[GreyGhost]

Zenimax

[joe-ilya]

Adrian Carmark

[glenzinho]

Bethesda

[Acid]

COMPET-N

[Gez]

I see ??? next to "big badasses" in the OP. Allow me to explain. First, play some nice background music to set the mood (click on Youtube vid), then read the quote below.

Once you beat the big badasses and clean out the moon base you're supposed to win, aren't you? Aren't you? Where's your fat reward and ticket home? What the hell is this? It's not supposed to end this way! It stinks like rotten meat, but looks like the lost Deimos base. Looks like you’re stuck on the shores of Hell. The only way out is through.