I found a Torgue rocket launcher named 'derp Duuurp!'.
I'm not sure what my favorite part of that name is. That they used two different spelling of derp, that the second durp is capitalized and needlessly elongated or that it ends with an exclamation point to make clear that this name must be shouted out in one's best impersonation of Mr. Torgue.
What's the coolest or funniest name you've gotten on a weapon? --- You're the stranger, ain'tcha? Are you looking for a nice, clean place to stay? Madam, I had a nice clean place to stay... and I left it, to come here.