As a practicing scientist and someone who has always been interested in history and the development of scientific ideas "The Structure of Scientific Revolutions" has for long time been the book that loomed large on my intellectual horizon. Thomas Khun's book has for a long time had a reputation as the definitive and seminal work on understanding how new scientific ideas come about and how and why they gain support. Part of my reluctance to start reading this book stemmed from my belief that it would be an overly philosophical work, with a lot of opaque technical jargon, and with very little relevance to actual scientific practice. However, to my great surprise and delight, nothing could be farther from the truth. This book is written in a very matter-of-fact style, and it is easy to understand what Khun is getting at. His own background in science and history of science probably made him very sensitive to the working and thinking of practicing scientists.
The insights that Khun has arrived at are still relevant almost half a century after this book has been published. The idea of "paradigm shifts" has even entered the mainstream consciousness, to the point that it can be caricatured in various cartoons and silly t-shirts. However, after reading this book it is not quite clear to me whether Khun wanted this to be a description of the way that science works, or more of a normative prescription for how to arrive at truly fundamental changes in some scientific discipline. This is particularly relevant for disciplines or directions of research that seem to have gotten stuck in some dead end, as has been the case with particle physics for several decades.
Whether you are a practicing scientist, someone interested in science, or someone who would like to know more about how scientific breakthroughs happen you'll greatly benefit from reading this book. You may not agree with Khun's every conclusion, but the longevity of the ideas presented here makes them relevant for every serious discussion about scientific endeavor.