I don't really have many Christmas tradition movies. Here's the best I can come up with:
Christmas Vacation (classic, of course)
A Christmas Story (so sick of this one, but it's ALWAYS ON around Christmas)
Harry Potter and the Philosopher's Stone (dunno why, but it's always been a Christmas tradition with us)
New to the list this year:
It's Always Sunny in Philadelphia: A Very Sunny Christmas (not for everyone, but hilarious nonetheless)