This Leadership Fable is really very good. I read it on a single plane travel, but it created a lasting impact on me nevertheless. It really very simply and gently provides you with insights in teamwork applicable in your work and personal life.
The structure of a fable (95% of the book) and the theory and exercises behind the model (5% of the book) seemed a bit strange to me at first, but it does work really well.
I truly believe that not finance, not strategy, not technology, but teamwork is the ultimate competitive advantage, both because it is so powerful and so rare.