"Christmas Unicorn" by Sufjan Stevens.
I know this isn't the most traditional Christmas song, but if you haven't heard it yet then please press play and go on the 12-minute 29-second journey.
It starts out playful ("I'm a Christmas Unicorn, in a uniform made of gold, with a billy-goat beard and a sorcerer's shield and mistletoe on my nose"), but also talks about the many elusive meanings of Christmas. Is a "pagan heresy", a "Christian holiday", or a time for "frantic shoppers"?
In the album description, Sufjan expresses his exhaustion of Christmas music but then asks: "So what is it about Christmas music that continues to agitate our aging heartstrings?" He then tries to answer his own question: "Maybe this: Christmas music does justice to a criminal world, marrying sacred and profane, bellowing obtuse prophecies of a Messiah in the very same blustery breath as a candy-coated TV-jingle advertising a string of lights and a slice of fruitcake."
So, in a sense, this is a Christmas song that is a commentary about Christmas songs. Which sounds really boring and pretentious.
BUT it's also just a really fun song! It spirals out of control with jingle bells and spacey-electronic-noises and a sweet breakdown beat. If you dance all the way through, I promise you'll get a really good workout.
Case in point, here's how I did the research for this response over breakfast (forgive the awkwardness, pajamas, and PDA):
When I get fatigued by the normal holiday songs, this reminds me that Christmas, crazy as it is, can still be magical. We're all Christmas unicorns. It's all right. I love you.