List your leadership book recommendations!

I am searching for leadership books that have impressed you and made a difference in the way you view your organization, co-workers, followers, etc.

"First, Break All the Rules"

I have enjoyed this book so far. I started reading it yesterday. For those that like books based on extensive research, this book offers goods backed by numbers. I have not looked at the testing, validity, etc., but the information seems reasonable. Here is a quote that caught my attention: "...people leave managers, not companies." That kind of puts more pressure on HR to find qualified candidates, not just quantifiable applicants. Find the right managers and they will save you money AND make your company a better place to work. I have not read the book yet, but it appears the book "The No Asshole Rule" may give some information on the topic.