Off the top of my head, I'm going to say the Dr. Who episode "The Doctor the Window and the Wardrobe" and the Psych episode "The Polarizing Express"

South Park : "Mr. Hankey's Xmas Classics" or Jeff Dunham's Holiday special.

All the Touched by an Angel christmas episodes that had Randy Travis in them.

American Dad when Stan and his family have an all out battle with Santa Claus :D

I love Lucy FIVE Santas or MASH Charles candy

snoopy and peanuts and the gang the one about that ugly old christmas tree thing