A non-Christmas movie favorite is Grease! because it was where my late DH and I went on our first date. The early show was sold out, so we went and had appetizers and drinks, and then went to the late show. Almost a year to the date after, we were married -- first date on June 26th, married the following year on June 23rd.
DH's birthday always fell around Thanksgiving and as a young child, DD wanted to take him to the movies for his birthday. As most parents know, there's almost always an animated flick released over Thanksgiving. To this day, DD and I (and sometimes DSIL) will take in a Disney, Pixar, or other movie to continue to celebrate his birthday.
When it comes to Christmas movies, the last few years I've made a list of 30 Christmas movies I'd like to watch. I'll try to watch one a day between Thanksgiving and Christmas. Some are the classics, others are ones I've grown up with, plus some of the sappy Hallmark movies. (I have a similar running list of Autumn-themed movies and do the same during the Holiday Grand Plan, using the list as a reward for completing my big task for the day.)