I know a lot of hard-core atheists believe in completely boycotting all things Christmas, since it represents the biggest clash of the secular and religious in society that the crusading atheist is rallying against.
Personally, I think that Christmas is such a mish-mash of Christianity, paganism and the secular, that you might as well enjoy those bits you can and ignore those aspects you don't believe in. For some that might be the religious side, for others it's the materialism.
Despite my relatively new-found atheism, I am still fascinated by the rituals and iconography of Christianity, and I love Christmas carols of all kinds, from the relatively secular (Santa Claus is Coming To Town) to the decidedly religious (Silent Night) and even those that are completely out of step with the Australian culture and climate (Winter Wonderland).
Anyway, here's the best version I've ever heard of The 12 Days of Christmas. These guys took one of the most tedious carols ever and turned it into something fun:
This is also a great opportunity to give the ol' Horde Santa icon a spin, since, yes, I am back on the Warcrack (although I'm playing Alliance, because the Draenei rock).