Programming Perl by Larry Wall, Tom Christiansen, and Randal Schwartz. "Gödel, Escher, Bach" was the book that taught me that computing could be inspiring and beautiful; "Programming Perl" was the book that taught me that computing could also be compelling and just plain fun. For the past two decades, the Perl language and the worldwide Perl community have provided me with employment, purpose, and companionship. And encountering this witty technical book (at a time when I was bogged down in my career as an unhappy C++ programmer) was what drew me into Perl in the first place.
-- Damian Conway