Can't go wrong with the
Futurama! Xmas episodes.
The
SNL Christmas compilations are pretty funny, as long as you don't over-watch them. I always loved the
It's a Wonderful Life alternate ending.
I think a few of my favorite sitcoms -
That 70s Show, Titus, 3rd Rock from the Sun - may have had one or two good Christmas episodes.
It's been a while, but I seem to remember there being an episode of
Excel Saga that takes place at Christmas time. I was always fond of that one - it's not every day you see an anime Christmas show, especially one so zany and stupid.