The double-barreled shotgun from doom2.
To me its the perfect implementation of a weapon in a fps.
It kinda sucks at long range and the reload is slow enough that you can't spam it. You will find yourself holding back and waiting for the perfect shot. When you get that perfect shot its devastating.
Nothing beats strafing around like a madman in doom2 and trying to line up the perfect shotgun blast that will drop your opponent right to their knees, blood pouring out from their neck. When its done right it kinda feels like jousting, they miss, you hit, and you are already so close that you will be moving past them as their body hits the floor.
Agreed. It's simply perfect. The only annoying thing, is that it's never enough ammo for it, so using it on the Cyberdemon is a bit difficult, and it's practically useless against the Spider Mastermind.