Hogfather

 Hogfather by Terry Pratchett, 433 pages.

This is the twentieth book (by order of publication) in Pratchett's Discworld series, a fantasy setting designed to be close enough to the real world to talk about it and close enough to the archetypal fantasy world to play in that space. In this book The Auditors (who audit reality and aren't very fond of the messiness of life) have hired assassins to kill the Hogfather, who bears a striking resemblance to Santa Claus. With the Hogfather unable to perform his duties, the anthropomorphic personification of death (usually just referred to as Death) must step in and do his job. Also while this is going on, Death's granddaughter catches on to what's going on and goes to try and stop the assassin (and associates) from breaking into the realm of the Tooth Fairy to further the whole killing the Hogfather plot.

If it wasn't obvious from that general description there's a whole lot going on in this book (there's actually a few more small subplots I didn't mention, like a whole college of wizards getting up to shenanigans). It's also a really good Christmas book that occasionally dips into the deeply profound. This mix of fun and sincere really works for me, and despite the fact that I definitely haven't read all twenty books preceding this one I found that it really worked on it's own. It's a little late for Christmas reading now, but I definitely recommend this one anyway.

(Fun Fact: There's also a tv movie from 2006 that is extremely funny and a pretty good adaptation overall)