1. The Pragmatic Programmer
Published way back in 1999, The Pragmatic Programmer: From Journeyman to Master is probably familiar to most developers. It's consistently included in lists like these, and with good reason: It is a thorough course on thinking and acting pragmatically.
Authors Andrew Hunt and David Thomas both have years of programming experience under their belts, and they've distilled the life lessons they've learned about coding in this indispensable book. Do yourself a favor and add it to your reading list.
20 years is a long time for any computing product, and that includes books. The authors have issued an all-new version for the modern computing world: The lessons remain the same, but The Pragmatic Programmer, 20th Anniversary Edition updates them for a totally new world of computing.