Noone even mentioned "Christmas Time (Don't Let The Bells End)" by The Darkness.
Granted, this is likely to be largely confined to the UK, since that's where they're from, and I wouldn't for a moment expect to see it represented on anything like this. But it's by far the most listenable Christmas song I know, to someone who is predominantly into rock music, and the only one I have actively acquired for my music collection.
Then again, 'easy listening' music (Worst. Misnomer. Ever.), including swing and big band styles, is the only type of music in which there are no songs that I can listen to and enjoy, or even listen to without getting angry (I'm prepared to listen to classical, punk, rap, metal, dance, and many things in between, as background to attempt to appear open-minded and/or tolerant), and sadly much of the Christmas song scene involves this aggravating genre. But just occasionally, I hear a Christmas-themed song that is original in some way, and it restores my hope that there are still talented people writing music, and that one day they will cease to be drowned out by the Frank Sinatras, and the Simon Cowells' latest performing pond life.