The first book on information architecture. A must-read, despite the absolutely hideous cover and book design.
A book that states the business case for interaction design, rather than teaches it. Great.
Sigh. Jakob annoys me more often than not, but he does come in handy to when you need to educate a client. This book gets bonus points because it is the first book that I’m aware of that includes my work (United.com refresh)
An absolute classic. While he's a bit of crank, this book is essential reading if you ever want to design anything.
There are few books on information architecture worth reading, but this is a good one.