Some of my Christmas favourites include:

Home Alone 1 & 2

It's a Wonderful Life

Merry Christmas Mr Lawrence (I'm posting about this tomorrow for our prompt :))

A Nightmare Before Christmas

Eyes Wide Shut

The Apartment

Batman Returns

Better Watch Out

Brazil

Carol

The Shop Around the Corner

Boiling Point

A Christmas Carol (Zemeckis' version)

Stalag 17

Not all of these are particularly happy or Christmassy lol but all involve Christmas in some way or another! And I love them all dearly.

I like digging into the stranger picks as Christmas comes around now. Some of the classics, of course, but some surprises too! A happy balance :)