I'm not sure why but I don't think Gremlins is widely thought of as an alternative Christmas classic. People recognise it as a bit of a classic but it isn't really categorised as a Christmas movie. This is wrong for a couple of reasons. Firstly it isn't just a bit of a classic it is an absolute classic. From the first moment Gizmo melts your heart to the assembled Gremlin army watching Snow White it's both hilarious, heartfelt and although it has a 15 certificate I'd say it's fun for the whole family (Just try not to use the word massacre at all). Secondly, the film has more to say about the modern concept of Christmas than almost any other recent Christmas film. It has a nice level of ambiguity both celebrating the modern Christmas and the American concept of Christmas whilst having the Gremlins represent rampant consumerism. Maybe like the Gremlins if you follow the rules / traditions things will be fine, it's when you compromise the problems start.
Although, the story of the Santa in the chimney is very dark....