I'll increase my number of favorite Christmas songs; most are parodies of well known Christmas songs, from Bob Thomas, Twisted Christmas.
I already mentioned the "Chimney Song," and I'll add "The Twelve Days of Christmas" parody, "Walking Around in Women's Underwear" (parody of Winter Wonderland), and "Teddy, the Red Nosed Senator" (Rudolph parody).
Good stuff if you like sick, twisted humor.