MY book of the year is the saddest book I've read:
Ivan Noble: Like a Hole in the Head
(
http://copac.ac.uk/search?isn=%200340864281&rn=1)
about the fight of the author against brain cancer.
It is a collection of diary entries that have first been published 2002-2005 on the BBC sites where they can still be read
(
http://news.bbc.co.uk/2/hi/health/2253201.stm).
The book is sad in itself, but greatly adding to the sadness was the fact that I knew the author; we've once worked together.