Never Split the Difference: Negotiating As If Your Life Depended On It by Chris Voss was recommended by a couple colleagues.  This is a great book on negotiation (and a bunch of related topics). Voss and Raz start each topic with a life-and-death hostage negotiation and then delve into the ideas behind the topic and where these apply in the less dire scenarios people face every day.  The authors use Voss' own experiences in the FBI as the lead international kidnapping negotiator, his research and studies into what makes negotiations work (or not), and his teaching and consulting work.  These elements are combined in a fairly engaging style: starting each chapter with a hostage situation made me want to keep reading to find out what happened, ... and learn a lot along the way.