I've often thought a great drinking game would be to take a sip every time Columbo says "Sir, or "Ma'am". I'm not sure I could last that long, sometimes he uses it 3 or 4 times in the same sentence. Lol
Also "Could you get to the point?" (The second Columbo / Nelson Hayward scene could really get someone in trouble.)
Of course you have to include "Oh and just one more thing" And anytime he mentions a family member or relative. And eats chili. Appearance by Dog. He whistles "this old man", or background music is played. Asks for a light or a pencil.