I'm just about to dig out The Dark is Rising, which I re-read every single Christmas. As well as being a fantastic book which evokes all sorts of childhood memories, it's also a sort of Christmas-porn. Not only is the narrative set over the Christmas/New Year period, it also describes my absolute platonic ideal of Christmas - lovely family (but not too twee) with all sorts of old-fashioned Christmas family traditions.
Anyway, it got me wondering, do other people always dig out the same books at Christmas, and, if so, which ones and why?