My favorite Christmas song is God Rest Ye Merry Gentlemen. I also really like Mary's Boy Child.
I like these two, as well.
"Oh Holy Night" -- A beautiful and powerful song whether or not one is a believer
Agreed. It's odd - I'm atheist, but I love Christmas music. I play the organ, and back when I lived in a house, I'd play this one, Do You Hear What I Hear?, and a whole bunch of others. I'd really crank up the volume and lose myself in it. My family never minded, which was fortunate.
These days I live in an apartment, so I can't do this anymore.
But I still write a lot of Star Trek filksongs to Christmas tunes.