Leadership Challenge by Kouzes & Posner

If validities are for you, this book is a must.  It highlights The Five Practices of Exemplary Leadership based on over two decades of research.  A must for everyone committed to leadership behaviors based on evidence, not fads.

Five Dysfunctions of A Team by Patrick Lencioni

This business fable is a classic.  It focuses on the critical elements of Team….trust, healthy conflict resolution, commitment, and results.

Take Back Your Life by McGhee & Wittry
Best time management systems using Outlook I know of!

Delivering Happiness by Hsieh
The best testimonial I know for intentional culture, and who isn’t interested in learning more about Zappo’s culture?

Getting To Yes by Fisher, Ury and Patton

The best book on WIN-WIN negotiations and outcomes.