Favorite Random Setup

What's your favorite joke where the setup is purely the means of delivering a joke that has no relevance to the plot?

Examples I always enjoy:

Leela wears a lime green tank top for the first and only time in the show
Bender: "Honey, I wouldn't talk about taste if I were wearing a lime green tank top"
Fry: "BAM!!"

Fry offers Bender a piece of gum for the first and only time in the show
Leela: "Ready to get to work, Bender?"
Bender: *spits gum at Leela's face*