The 7 Habits of Highly Effective People — Covey (1989)

Stephen Covey's The 7 Habits of Highly Effective People (1989) has sold 40 million copies and remains one of the most read business books in corporate America. Its framework — from dependence through independence to interdependence — and its distinction between urgent vs. important tasks (the Eisenhower Matrix) provide a genuinely comprehensive approach to both personal effectiveness and leadership that has proven durable across decades of cultural change.