I'll go real immature and name them all "your mom"

I'm going to have a shotgun called Larks Tongue and a Gauss Rifle named Tarkus.

Laser sniper rifle: Nikola's Finger

Automatic Laser rifle: Nikola's Fury

Silent but Deadly

A laser rifle named "This Machine Evaporates Commies"

And if http://fallout.wikia.com/wiki/.223_pistol ever makes its return I think I'll name it either "Rick" or "Horselover Fats"

An automatic shotgun called The Street Sweeper.

(Assuming it's possible to make an automatic shotgun.)

The Berserker would be a good fit, too.

"This Machine Kills Commies"

I love that, http://www.gamesas.com/user/944207-effehezepe/.

A combat shotgun called "Trevor's Terrible Shotgun"

Probably the corny stuff that I normally name my weapons like "Protector" and "Defender" or something else that suits the weapon specifically (like a baseball bat called Home Base) as well as one named after the spouse if she is dead and the companion, if any, that I romance.

A sniper rifle named Tears in the Rain.