Can't beat a bit of Rare Exports for some Nordic Christmas horror, tainted with black comedy.
And I agree with the Cheeky one that It's a Wonderful Life is a ruddy depressing piece. I can't say I loved it when seeing it a few years back, for that reason.
I might make a Powell & Pressburger doublebill of it. Fantastical and deeply moving stuff with The Life and Death of Colonel Blimp and A Matter of Life and Death.
Muppets' Christmas Carol
A Nightmare Before Christmas
Elf
Home Alone
Love Actually (I know, I know: it's a load of old sentimental bollocks, but I LOVE it).