I know the Mariah Carey song is hated because its overused, but its also objectively a well produced piece of pop music.
My favorite though is O Holy Night. Performed well I want to stop and listen to it. It moves me, and I dont give enough of a fuck about religion to call myself an athiest.
I celebrate Christmas (not as festive as some people but still) but I generally am apathetic to Christmas music at best. That being said, Carol of the Bells by Transiberian Orchestra still kicks ass and I would say it is the one Christmas song that I would actively and willingly listen to.