Every December I watch a copy of The Ref; this year was the first time I had my own copy and didn't need to rent it. What kept me? It's a great film that I wouldn't really call a Christmas film - it just happens to take place around Christmastime.
Denis Leary is a burglar who takes Judy Davis and Kevin Spacey hostage, and their constant bickering is enough to drive him up the wall. Davis & Spacey do some excellent work, and while, as Leonard Maltin says, it's a meatier movie than you might expect, there are some great laughs and semi-silly scenes as well. Here, for instance, Spacey finally takes on his guilt-tripping mother - and wins.
Love Actually is considered more a romantic comedy than a Christmas movie, as there are six to eight romantic comedies crammed into it. The one where a guy loves his best friend's wife is resolved this way.
Sappy? Maybe. But the reason they make syrup out of sap is because it's oh so sweet.
PS - R.I.P. Dan Fogelberg.