The classic mid-70s popular philosophy book. I think I'd read this before when I was 14 or so; I remembered much of the story but none of the philosophy, and I suspect the critique of academia didn't really click the first time I read it. This is the 25th anniversary edition, which has some extra material in the back including some correspondence with the book's editor, a new introduction, an interview with Pirsig and some fixed typography; the interview's particularly interesting.
I may disagree with some of the conclusions Pirsig -- or, rather, Phaedrus -- comes to, but this is still a great book, and an entertaining and persuasive read, and the commentary on the search for Quality in technology rings as true today as it did in 1974. Thoroughly recommended.
ISBN 0099322617.