The balance between flashbacks to Christmas past ( and the great child actors who played the boys, they really got the feeling of the characters), the current crisis with the mysterious holiday themed deaths and the impending doom of Dean (it's to be his last Christmas) was all very well handled and the story was very balanced.
The whole concept of the Anti-Claus was a great first theory, the visuals of the bad Santa arriving with his bloody bag, taking victims up the chimney and the whole thumping on the roof routine was great, and creepy as hell. Much better than any of the so called Christmas slasher movies. Finding out that it is really pagan gods who are responsible, and that they live as this terribly sweet and Cleaveresque family was too much. The whole concept was hilarious, and as gruesome the torture scene was, Dean spouting his profanity and being reprimanded and then spouting out his Fudge rant was too much... I love these guys and their witty sense of humor, and love them even more when they play the gay couple. Sam going on about the "yummy" wreath that they were looking for was too much, but it's Dean's expressions that have me in hysterics.
Of course all's well that ends well, and the Winchester boys manage to get out of their holiday nightmare, dispatching the pagans with a Christmas tree (too ironic) before settling down to a holiday together, complete with the best gifts that you can find at the local Gas Station and bittersweet memories of holidays past, and of course the hope that there will be another one next year.