Same here; it depends on the mood/situation etc...I don't think I could pick just one....
e.g. Sh!t faced on a Christmas night out it has to be Slade or Wizzard. Driving home on Christmas eve it has to be, well, Chris Rea! Christmas morning when I want to get a bit sentimental about past Christmases is for a bit of Johnny Mathis; etc. etc...