Overall I generally like more light hearted Christmas movies instead of the more drama or romance filled ones. I also prefer the more classic stories. So my top three are
National Lampoon's Christmas Vacation,
The Night They Saved Christmas, and
How the Grinch Stole Christmas(the classic 1966 version) with an honorable mention to
A Christmas Carol with Patrick Stewart as Scrooge.
National Lampoon's Christmas Vacation is funny and brings the zany antics of family vacation to the Christmas season. I am also a bit of a sucker for parent tries for perfect Christmas and everything goes horribly but hilariously wrong trope.
How the Grinch stole Christmas is what other versions tried to copy. The one with Jim Carrey was well done and makes a good transition from cartoon to live action but at the same time I always felt that the cartoon was better. I am sure growing up watching the carton has colored my view some but at one point I knew the entire movie by heart.
The last of my favorites is the Night They Saved Christmas. It is about a family that must save the North Pole from a mining company before they blow up Santa's Workshop. Overall it is a cheesy movie that has fairly bad acting which would normally disqualify it. The movie makes my favorite list more out of nostalgia and the fact that like Sharknado it crosses the line from so bad to funny to watch.
There are also dozens of Christmas Carol plays and movies that come out every year. This one is my favorite because of the acting. The plot and effect are about the same as most live action version. The thing that pushes forward is Patrick Stewart showing he can be more then a cool starship captain and Richard Grant pulling off great performances that make a known story seem new again.
I know it is an internet meme that Die Hard is a christmas movie but overall I don't think it really counts. The only christmas part is that starts at a christmas party before the terrorists arrive. It doesn't involve any of the hallmarks like Santa, reindeer, or even the more reglious aspects. It is a great action movie that takes place during Christmas but I just can't count it as Christmas movie.