what shows never had a Christmas episode that you know of?

F Troop
The Munsters
Hogan's Heroes
Soap

Leave It To Beaver

Did My Three Sons have a Christmas episode?

no, I don't think they did.

"DALLAS" never had one, and "GET SMART", nor any of the "STAR TREK" shows (a shame, because that would have been great-I can just hear Worf say "What is this thing you call-Christmas"? and "I am a Klingon-we do not get-"Merry"!)
none of the "C.S.I." shows ever did.

I don't think "The Cosby show" had one either.

I don't think Get Smart had one.

EDIT: Nevermind, I just saw that someone already posted that, LOL.

My Wife & Kids

I don't think "The Cosby show" had one either.
They had one later on. Didn't Clair get her own room/office of some sort? And Theo would show off the lights outside.

Really? Well, I'll check it out.

Benson

Benson
They made one too. It's called "Mary and Her Lambs."

I do not remember Mary and her Lambs

I do not remember Mary and her Lambs
It's an episode from season 4 where Benson helps Kraus keep her foster children.

They had one later on. Didn't Clair get her own room/office of some sort? And Theo would show off the lights outside.
Yes they did! But it wasn't an official Xmas episode!