It isn't precisely an insult, but there's Ward Fowler'a line that goes something like "Look, let's stop pretending that I'm brilliant and you're stupid."

That one line covers so much about Columbo's behavior towards a killer.

Ken Franklin to Columbo: "I love to see a man raise with no cards in his hand."

Just because he's played by Ray Milland (who was so great at playing smug characters), Jarvis Goodland has some catchy ones. Even though it isn't said to Columbo himself, there's "That Neanderthal lieutenant."
It might not be that original, but Milland makes the most of it.