if you have a robust attitude to bad language, you could do worse that Kevin Wilson, who has a whole album of rather, erm, unique ditties. Can't name the tracks here as the editor's pen will be working overtime! Traklisting here http://www.townsend-records.co.uk/product.php?pId=100001 13&pType=music
Bob Rivers (Twisted Tunes) are pretty damned good, also try American comedian Bill Engvall (he doesn't have many Xmas songs, but his normal stuff is really funny!).