"This ultimately wonderful classic is truly the most inspirational first-person shooter ever created, and if you had to choose between Doom and another game, I don't care what it is, Doom would always be the winner."
- David Keyes
"In 1993, we fully expect to be the number one cause of decreased productivity in businesses around the world."
"I remember playing Doom 'til 3 o'clock in the morning. It was the first time I had ever been frightened while I was using a computer. And it really opened my eyes - experiences like that are why we play computer games."
"Those seeking the ultimate in home demon protection can now protect their plane of existence with a double-barreled, pump-action combat shotgun that blasts more holes than Mobil Oil."
- "Doom feels more like 1st person Robotron than a modern FPS"
- "Doom is about “maneuverability as defense”"
- "Doom has a more varied bestiary than most modern FPSes"
- "Doom was abstract in ways that empowered its level design"
- "Doom enabled a revolution in player-generated content"
- "Doom is one of many classics whose less obvious qualities are seldom revisited"
"There is a scene in 'The Color of Money' where Tom Cruise shows up at a pool hall with a custom pool cue in a case. 'What do you have in there?' asks someone. 'Doom.' replied Cruise with a cocky grin. That, and the resulting carnage, was how I viewed us springing the game on the industry."
- John Carmack on why the game was named "Doom"
"Bobby Prince was a lawyer before he was a musician. He knew the legal amount of sampling that he could do without getting into trouble."
"I jumped out of my seat the first time I saw one of those pink bruisers, and I cringed when I heard the imps the first time - but when I walked out into that big arena with that rocket spewing giant chasing me down I literally broke out in a cold sweat. Nothing before or since has induced that same mix of adrenaline fueled terror."
- Mark Terrano on the Cyberdemon
"Gabe [Newell] tells it this way. When he was at Microsoft in the early 90’s, he commissioned a survey of what was actually installed on users’ PCs. The second most widely installed software was Windows.
Number one was Id’s Doom."
- Michael Abrash 
"His sound would cause great fear during my gaming sessions. Upon discovery of this character I felt frozen watching him methodically reanimating his brethrens one by one. Carefully he walked to each of the fallen corpses summoning his endless energy into the once lifeless body calling upon it to walk again. The feeling of helplessness combined with a shear state of panic had set in. If left unattended he would resurrect all of the characters I had painstaking silenced one by one. If I was to confront him, I was surly to become engulfed in flames and loose all sense of direction looking for the nearest corner to block his line of sight. If unsuccessful in my search for shelter, I would be dealt with swiftly and forcibly by a power so great I would surly be catapulted high in the air and my lifeless body left to fall to the floor. I'm talking about no other then the Arch-Vile of Doom II."
- Paul Butterfield
"Give a man a fish, and you'll feed him for a day; teach a man to play Doom, and you'll never get another day's work out of him."
"An old Doom map was the inspiration for 2forts, as well as TF itself"
"Along with Doom II, we also saw the first traces of multiplayer gaming. Playing it against your friend was something so different, and that is also why we continued to play today."
"The penalty for cutting corners, forgetting textures, etc, is usually the same: your level screws up. DOOM's engine never knows 'what you really meant.'
Hopefully future editor releases will get better and better at doing these consistency checks for us. In the meantime, use the coprocessor mounted on your neck. :-)"
- Tom Neff, March 1994