The Peter Principle is often described as a classic of institutional analysis. Many cited in the workplace (especially for denigrating his superiors) but few actually read. This book is a reference in my opinion, despite the fact that it was written in the late 60s; ideas and analyzes developed remain relevant despite changes in working structures since.
Furthermore, it seems important to stress that the central theme of the book covers the hierarchical social organizations and goes beyond the professional setting.
I had a great time reading this book I consult again occasionally.