I thought there was already a thread along this line but I couldn't find it.
I was just watching Bye Bye Sky High IQ Murder and Columbo says something like "here I am talking to some of the most intelligent people in the world and I didn't even know it" LOL
Another one is from Murder Smoke and Shadows, the killer says, "so you think it's murder?" Columbo replies, "Well, I expect it was something like murder. It would have been a very strange electrocution if the victim got up and turned his pockets out, and then took hisself to the beach and hit hisself in the face, if you get my drift, sir."
Another one where the killer is the smartass is Abigail Mitchell, seeing them make the plaster cast of the footprints, she says, "well we do know Edmund was here, remember he was found dead in my safe." :-)
To Miss Hudson in Prescription: "Whatsamatter, haven't you seen a pair of sunglasses before?"
To McGoohan in ID Crisis: "You know, I get the distinct feeling someone's been following me. It can't be the collection agency - the car's paid for." (( sly whistle as he backs away ))
In IQ: "And the gun . . just snapped away up the chimney all by itself."
After they've been looking for Hayward for some time a patrolman finally tells Columbo "Det Columbo we found Hayward. He was at home" Columbo says "took a long time to find him at home"
Another one of my favorites fittingly comes from A Stitch In Crime where Columbo and Mayfield are talking about the roommate Marcia and Mayfield suggests that maybe she knows more than she's saying and Columbo replies "actually sir I think she knows less than she's saying"
trivia
Nita Talbot who played Marcia was once married to Don Gordon who played Alvin Deschler in Negative Reaction.
I love the line in Murder Under Glass when Paul Gerard asks why Columbo thinks Vittorio was in some kind of trouble, and Columbo replies:
"Mainly because he was murdered, sir. The two, trouble and murder, they seem to go together. At least that's been my experience, sir."