Just a quick FYI ---Amazon is giving away a free Christmas song on MP3 everyday through Christmas. Yay! You can get such greatest hits as Twisted Sister's Deck the Halls. I hurt my neck from all the head banging I just did. :-)
There's also some more normal ones too like Mannheim Steamroller's gorgeous rendition of Greensleeves, a pretty version of O Holy Night by someone named Leigh Nash, and Celtic Woman (they're always on PBS!) singing Ave Maria.