I want to be.. The VERY BEST!!!

[Aqua Kitty]

Revenants.

What's the coolest type of weapon out there? Explosives.
Revenants have infinite-ammo endless rocket launchers strapped to their shoulders. They don't care about dying--they're already dead. In fact, they flipped off death and came back as a skeleton, then strapped rocket launchers to themselves because they don't have to care about the backblast anymore. What's that? They're the most dangerous FPS weapon for people to wield? GIVE ME TWO, FAGGOTS.
They can fire Awesome Rockets, which fly over and blow whatever up in the typical way that rockets work in FPSes, or they can fire Jackass-Hunting Rockets, which act in no logical way and arc and spin around whatever victim they can find until they shove themselves right up the victim's ass. It must be powered by Nyancats, since it's just as painful and forced.
Just in case anyone is still standing as a final "fuck you" to the awesomeness as explosives, Revenants have a nasty right hook that rivals the power of the Berserk pack, able to cleave straight through any aspiring armored marine in about three good hits. And this is the same marine that can take fifty rockets, fireballs, claws, and whatever to his face and keep on trucking, so the Revenant is packing some serious muscle on that bone.

In fact, when the battle's going wrong for them, they still don't give a shit. The Revenant is the monster with the highest pain chance--even just whapping your flimsy fist against the non-existent groin is going to elicit a reaction out of them. Despite that the Revenant has no more muscles, no more nerve endings, nothing that would logically elicit any sort of pain for them, it still reacts from your little ticklefist and plink-bullets. Why?
The only answer is that they just don't give a shit. Oh, you're hitting it, oh no! Oh, you're shooting it, oh no! Excuse me while I lean back and laugh in that "UUWEEEHHH" voiceclip.
Even when they finally die, they don't care enough to give a death scream or rattle--they just flop back on the ground, their bones crumpling, without any cry or protest. And why SHOULD they care? They've died before, and came back perfectly fine. Hell, they didn't even need an Archvile for it. Anyone else that protests are either pussies, or wimps, or both. Just put them back together and hook a backpack on it, and they're good to go.

They're also the hottest commodity among the fine ladies of Hell. Why?
Their entire body is made of boners.

Pretty much this.

[-Jes-]

Archvile reporting in

This.

[ibm5155]

thinking better I would be super cool to be an archvile *--*
think, you could crouch and just hit a guy that is 100km from you bu you can se he :D you can respawn the dead monsters for have fun on the bored times

why would i require a sniper if my fire never wrong when I aim :D

[Gardevoir]

Heh, the only one and the greatest...

ROMERO HEAD ON STICK!!!!!!1111111111

...on second thought, a Barrel.

[CloudFlash]

Yurei. Free titties, cute long hair, can become invisible. OH GOD WHY

[President People]

Heaven Guard

Dark Bishop

If we're talking strictly DooM/DooM II monsters, then it's the Baron of Hell. I was utterly intimidated by the roar these guys made when I first encountered them. It seemed like they'd never go down as they swaggered out of their twin compartments in DooM. Seriously, look at the swag in their step.

[Igor]

IGOR WOULD BE A NAZI.
OR A BARREL

OH I KNOW, A BARREL FULL OF NAZIS

[massacrebosco]

Any monsters with DoomGuy helmet !! :3

[Cruduxy]

Heretic's Iron liches, because a freaking epic smile and a pain down the throat for anyone who didn't learn to strafe dodge yet...

[Medicris]

Yurei. Free titties, cute long hair, can become invisible. OH GOD WHY

Yeah, you're also cold, dead, rotting, and most likely have all kinds of nasty diseases and parasites in your deceased flesh. And that hair's so greasy it could be squeezed out and used as WD-40.

Sounds like... fun. :|

[Laggy Blazko]

Former commando. I'd have a cool bloody beard and a nice "pistol". =P

[blackmario]

a cyberdemon so i could blow shit up with my rockets :D

[Orangestar]

Weightlifter12 WARNING: Video contains language unsuitable for young children.

[Zupoman]

Weightlifter12 WARNING: Video contains language unsuitable for young children.

Ohhhh, this monster is from Doomguy Warzone made by Doomguy 2000! (this is another famous horrible wad creator, like Terry).

Yeah I surely would love to be it...

[Doomkid]

I'm sure I'm not the only one who would like to be quite a few of these.. But if we're talking effectiveness, those damn demons in Brutal Doom where you can only see their eyes.. So damn cheap, yet effective and surprising as hell, plus it would be awesome to have chompers that huge. No one's gonna fuck with that.

But then again the Baron of Hells are very intimidating, as President People said. And what about an Arch Vile? A human brain behind that flame attack ability would just be absurdly powerful!

[Cruduxy]

And what about an Arch Vile? A human brain behind that flame attack ability would just be absurdly powerful!

Someone didn't play Internal Conflict! But yeah human archviles are way more dangerous...

[Spider]

I would be a Spider Mastermind, because my name is dedicated to that monster and why not? A giant cybernetic 4-legged arach-like brain with a mega-chaingun, I would go out and slaughter everyone. hehe

[-Jes-]

And what about an Arch Vile? A human brain behind that flame attack ability would just be absurdly powerful!

Someone didn't play Internal Conflict! But yeah human archviles are way more dangerous...

If you think IC's vile was potent, you should try Master of Puppets'.