My musical tatses are pretty diverse, i like Ella Fitzgerald and Glenn Miller, i also like Black Sabbath, Judas Priest and Slayer. Also a huge fan of Korn, Slipknot and Dimmu Borgir.
It's tough to choose, but my fave Xmas song of all time is proably Fairytale of New York. But Stop the Cavalry and I believe in Father Christmas come close second.
To steal a quote from Terry Pratchetts The Hogfather (about Hogswatch): "It should be Jolly, with mistletoe and Holly, and..other things ending in 'olly' "
I think the only song released in recent years that comes close to matching the magic of Slade and Wizzard is Christmas Time (don't let the bells end) by The Drakness, that's a magical Xmas song. You should totally have a little chorus of kids singing in the background!