Slade's "Merry Xmas, Everybody" is one of the all-time great rock Christmas songs, but it's unusual in that it never received much attention (or at least I'd never heard of it) until the past decade or so. Had Slade fallen in favor that much? No matter, we've been making up for lost time with a big resurgence in this one, and it's unquestionably a favorite. I know that in the U.K. it's almost like "White Christmas", and it may even be the better song. Yes, I did just say that.
It's also worth noting that the entire Christmas Day '74 episode of Top of the Pops (where this clip come from) is available in segments on You Tube. Great stuff.