The Race to Truth by Emma O'Reilly. It tells the story of how Lance Armstrong's soigneur changed from being a big Lance fan into a Lance hater and finally back to a balanced view of him. In the last chapter she outlines how she made peace with Lance and she even argues that his lifetime ban from sport is too severe. Overall I think it is a very interesting and well written book (apparently she had no ghost writer).
It is an interesting contrast to Seven Deadly Sins by David Walshe which I read earlier this year. David Walshe clearly views Lance Armstrong as cycling's enemy number one and he shows no sympathy with the view that Lance was simply part of a cycling culture which almost required doping.