I don't know exact quotations, because I watch Columbo with sub-titles, but I like the way how does Nelson Brenner in Identity crisis.He says it very polite and slowly, saying sth similar to "I'm a very important man and also very busy", it's a very simple and polite sentence, but it tells Columbo he shouldn't appear anymore or he'll be in troubles.

I think that Mark Halperin is also very arrogant to Columbo ever since he investigates the case.

Harold Van Wyck says something along the lines of, "Perhaps you should just move into one of the guest rooms."

Virtually everything said by Mrs. Peck!