I revert to 3rd grade mode after about a month of carols. "Walking 'Round in Women's Underwear" is a personal favorite, sung along with the radio, only loudly and off-key. "Jingle Bells, Santa Smells" is another fav.
Drives Mrs WBill nuts. Wbill Jr. thinks it's funny, though. :-) I've not reached the "Sheesh, you're a Dork, Dad" stage yet.