The Shop Around the Corner! I'll admit, I totally have a hardcore crush on Jimmy Stewart in this movie.
Also, Love, Actually, which satisfies practically every desire in a Christmas movie: romance, humor, tearjerkiness, cheesiness.
And I have a soft spot for the Santa Clause movies. If they're on, I'll watch 'em.
And, not a holiday movie per se, but I always have a yen to watch Auntie Mame at this time of year. It does have a Christmas scene!