My favorite funny Christmas song is "Chiron Beta Prime" by Jonathan Coulton.
My favorite serious Christmas song is "Thanks for Christmas" by XTC, recording under the pseudonym "The Three Wise Men".
Although really, in December, when I'm out somewhere eating lunch, my absolute favorite songs are not Christmas songs; they're anything that's a break from the relentless Christmas-holiday-jingle-bells-Santa-Rudolph-ad-nauseam public soundtrack.
Pinkie Pie As cute and quirky as a pony on a unicycle, with more energy and exuberance than an all-you-can-eat sugar rush, you can't help but naturally be the one that stands out from the crowd. And you don't mind! In fact you're usually have too much fun to even notice those other ponies staring at you. You love life and keep looking at it through those rose-tinted (or should I say pink-tinted) specs! And what's the point in being happy if you can't spread the cheer with others? With your gift of wonderful silliness you can bring a smile to anyone's face and help turn those frowns upside-down.