I must confess my wife and i do this sometimes where something comes up in a conversation and we'll answer with a Columbo reference....
Examples...............

If my wife asks me to get her a glass of wine, i might say something like.."i feel honored your letting me decant"

or

If she's putting on night cream, i might say something like, " it's like a miracle, wrinkles just disappear and it lasts all day"

etc.

We must have all done 'just one more thing' I have also done 'don't count on that' to employees when they are trying to take advantage of my good nature!

I don't know if I've ever done it out loud, but when it sounds like someone is making a lot of false assumptions, I feel like quoting Milo Janus by saying "Cigar ashes!"

(It's a lot more original than "B.S.!" - either the initials or the actual phrase!)

No but some from other characters. "It wasn't premeditated" "I have a perverse affection for..." "Do you really believe those crazy things you are saying?"

Nope. I think for myself, but I can see why your ilk would.

"I'll have the chili; with beans ,without beans...it doesn't matta"

It isn't direct quotations, but every time I ask very hopefully if something is a lot less expensive than it turns out to be, I feel like I'm quoting Columbo.

J.P. Morgan once said, "if you have to ask the price, you can't afford it"

as Donald Pleasance reminded Columbo in 'Any old Port in a storm'.

Yes, and before that, General Hollister uses the quote in DEAD WEIGHT.
But I'm with Columbo - asking the price almost always makes sense.

There are so many lines that I would like to use, but most of them would require a very unique context.
In a way, I hope someday someone will ask me, "What's going down?", so I can respond with Joe Devlin's classic line, "The world, in terminal descent."

I've always wanted to say things sarcastically exactly like Donald Pleasence. In the case of ANY OLD PORT IN A STORM, there's his very simple line "Re-markable."
(In the film NIGHT OF THE GENERALS - which is also a murder story - Donald has a whole "repertoire" of sarcastic lines, and in his case it isn't just the lines, it's his great delivery.)

I just used a line that I loved from "Last salute to the Commodore". We were talking at work about how much sleep we get, I used Columbo's "I gotta have my eight".

Ive used the term moral junkyard a few times as per Rumford...
and it being summer...if I sweat in the car before the AC kicks in..I think of Jesse Jerome in his high back leather chair