My personal favorite is 'White Christmas'. My sister and I usually watch it together, it reminds us of our Grampa.
I also love more contemporary films like 'Love, Actually' and 'The Family Stone'
This weekend I have a date with my Best Bear (he is having a particularly tough surgery on Friday and won't be feeling so well this weekend) - his request is that we watch the old kids classics: 'Rudolf', 'Frosty' and his absolute favorite 'Emmet Otter's Jug Band Christmas'