Stephen Colbert's Christmas Special had be crying I was laughing so hard. Maybe you have to be old enough to remember the sort of Christmas specials he is mocking (I am). He announces the special guest by name - so hokey, so what Bing et. al. used to do!
But there other great mocking going on too. It was really funny and should become a classic up there with the Grinch, Charlie and Rudolph.
Here's one funny bit:
Unfortunately, the funniest song was sung by Fiest (whom I'd never heard of, but whatever) as an angel putting a prayer request on hold a la any customer service line. It was hilarious and brillant.