Dual wielding Beretta 92Fs from any Max Payne game. Forget accuracy and finesse, there is nothing that feels nearly as good as unleashing a personal John Woo bullet hell on some poor mook's unsuspecting fizzog.
The Iaito from Dark Souls. It may not be the best weapon in the game, but finishing an opponent off with dat R2
never ever gets old.
The Hand-cannon from Bioshock Infinite. I felt that most of the guns (and, indeed, the shooting) in BI was pretty generic, until I got my hands on this bad boy. There is something about it's kick and heft that makes every trigger pull feel apocalyptically satsifying! Also, reminds me of Roland Deschain from The Dark Tower series.
Hitman's Fibre Wire. Barring the accidental deaths introduced in Blood Money, this is the weapon of a true professional; up close and personal. This simple, yet elegant tool of death always brings a sociopathic smile to my face, just as it brings a purple-reddish tinge to my mark's.
Another Hitman weapon, this one introduced during Blood Money. Nearly as satisfying as the fibre wire but for entirely different reasons. Come on, who here didn't bury a Kitchen Devil into drunk Santa's face at range during "You Better Watch Out"...?