You must have been reading my mind because I was thinking of starting this same thread the other day!
Some of these are kind of corny and would only make sense to me, but...
Elf
Prancer (a fave from when I was a kid)
Home Alone (I don't know why!)
It's a Wonderful Life
A Disney Christmas
The Harry Potter Movies (but really, I watch them all year anyway)
And the absolute MUST, one of my favorite movies ever......
A Christmas Story! Hubby and I make a point not to watch it until Christmas Eve, after the kiddo is sleeping and we are waiting for Santa...
You gotta love Ralphie!