The only Christmas TV special that I watch anymore is "Olive the Other Reindeer", simply because it's the most twisted Christmas cartoon I've ever seen. Some of the characters are drawn positively picasso-esque, and any special with a cameo by Michael Stipe as an angry reindeer is okay with me.
As far as the others - Rudolph, the Grinch, etc. - meh. I used to watch them every year, but a few years back, I realized that once you've seen a show ten or twenty times, it's really no longer required watching.
I like the 1970 movie version of Scrooge, with Albert Finney. I've got an old tape of SNL Christmas skits that I usually watch every year. And I usually watch "The Homecoming", the original "Waltons" movie, every Christmas. Oh, and "Love, Actually", because while it's not actually a Christmas movie, it is set in the Christmas season, and it's really cute.
How about you? What's your favorite Christmas TV special/movie? Least favorite?