My favorite scene was done during "Police Rookie School" when they perform the "Mustard Sketch." They performed it in The Noose Hangs High, but I think the timing done during the series episode was simply perfect.

Bud: "Mustard and hot dogs go together!"
Lou: "Let 'em go together, I don't wanna split up any romance!"

Years ago I recorded the routine onto audio tape and listened to it repeatedly in the car. My brother and I memorized it, and one day we were driving with my girlfriend at the time and went right into it. She had never heard the routine before and thought we were really getting into an argument, but at the same time couldn't stop laughing.
"I live the unknown, I love the unknown... I AM the unknown."