Universal Principles of Design
by William Lidwell | 
100 Things Every Designer Needs to Know About People
by Susan Weinschenk | 
The Essential Guide to User Interface Design
by Wilbert O. Galitz | 
Small Things Considered
by Henry Petroski | 
Cradle to Cradle
by William McDonough | 
Presentation Zen
by Garr Reynolds | 
Designing for Behavior Change
by Stephen Wendel | 
Resonate
by Nancy Duarte | 
Creative Confidence
by Tom Kelley | 
Designing Interfaces
by Jenifer Tidwell | 
100 Ideas That Changed Graphic Design
by Steven Heller | 
Visual Complexity
by Manuel Lima |
The Amazing Book is Not on Fire
by Dan Howell |
Code Complete
by Steve McConnell |
Destiny of Souls
by Michael Newton | 
The Simple Path to Wealth
by J. L. Collins | 
Firefly
by Joss Whedon | 
The Way I Heard It
by Mike Rowe |
Refactoring
by Martin Fowler | 
Effective Java
by Joshua Bloch |
Anyone who designs anything to be used by humans -- from physical objects to computer programs to conceptual tools -- must read this book, and it is an equally tremendous read for anyone who has to use anything created by another human. It could forever change how you experience and interact with your physical surroundings, open your eyes to the perversity of bad design and the desirability of good design, and raise your expectations about how things should be designed.