The Innovator's Dilemma — Clayton Christensen (1997)

Clayton Christensen's The Innovator's Dilemma is the most influential business book of the last 30 years and the standard reference for understanding why market leaders consistently fail to adapt to disruptive innovation. Its framework — "disruptive" versus "sustaining" innovation — has become part of the standard vocabulary of technology strategy and is cited by every major technology investor and entrepreneur as a foundational text.