The Effective Executive: The Definitive Guide to Getting the Right Things Done
Peter F. Drucker

5/5
A 1967 classic on personal effectiveness, written by the man who invented the term "knowledge worker". This book is full of important ideas, and is quite clearly the trunk off of which the modern productivity genre has branched. Peter argues that an effective executive knows where their time goes, focuses on the output of their work rather than the work itself, builds on their strengths, concentrates on high-leverage activities, and makes effective decisions. This book is a how-to manual for each of these behaviours that has aged surprisingly well.