I've gathered all the book titles in this thread and created Amazon affiliate links (if you don't mind. Otherwise you still have all the titles together :-) )

A Pattern Language, Alexander and Ishikawa and Silverstein http://amzn.to/2s9aSSc

Advanced Programming in the Unix Environment , Stevens http://amzn.to/2qPOMjN

Algorithmics: the Spirit of Computing, Harel http://amzn.to/2rW5FNS

Applied Crytography, Wiley http://amzn.to/2rsULxS

Clean Code, Martin http://amzn.to/2sIOWtQ

Clean Coder, Martin http://amzn.to/2rWgbEP

Code Complete, McConnel http://amzn.to/2qSUIwE

Code: The Hidden Language of Computer Hardware and Software, Petzold http://amzn.to/2rWfR9d

Coders at Work, Seibel http://amzn.to/2qPCasZ

Compilers: Principles, Techniques, & Tools, Aho http://amzn.to/2rCSUVA

Computer Systems: A Programmer's Perspective, O'Hallaron and Bryant http://amzn.to/2qPY5jH

Data Flow Analysis: Theory and Practice, Khedker http://amzn.to/2qTnSvr

Dependency Injection in .NET, Seemann http://amzn.to/2rCz0tV

Domain Driven Design, Evans http://amzn.to/2sIGM4N

Fundamentals of Wireless Communication, Tse and Viswanath http://amzn.to/2rCTmTM

Genetic Programming: An Intrduction, Banzhaf http://amzn.to/2s9sdut

Head First Design Patterns, O'Reilly http://amzn.to/2rCISUB

Implementing Domain-Driven Design, Vernon http://amzn.to/2qQ2G5u

Intrduction to Algorithms, CLRS http://amzn.to/2qXmSBU

Introduction to General Systems Thinking, Weinberg http://amzn.to/2qTuGJw

Joy of Clojure, Fogus and Houser http://amzn.to/2qPL4qr

Let over Lambda, Hoyte http://amzn.to/2rWljcp

Operating Systems: Design and Implementation, Tanenbaum http://amzn.to/2rKudsw

Parsing Techniques, Grune and Jacobs http://amzn.to/2rKNXfn

Peopleware: Productive Projects and Teams, DeMarco and Lister http://amzn.to/2qTu86F

Programming Pearls, Bentley http://amzn.to/2sIRPe9

Software Process Design: Out of the Tar Pit, McGraw-Hill http://amzn.to/2rVX0v0

Software Runaways, Glass http://amzn.to/2qT2mHn

Sorting and Searching, Knuth http://amzn.to/2qQ4NWQ

Structure and Interpretation of Computer Programs, Abelson and Sussman http://amzn.to/2qTflsk

The Art of Unit Testing, Manning http://amzn.to/2rsERDu

The Art of Unix Programming, ESR http://amzn.to/2sIAXUZ

The Design of Design: Essays from a Computer Scientist, Brooks http://amzn.to/2rsPjev

The Effective Engineer, Lau http://amzn.to/2s9fY0X

The Elements of Style, Strunk and White http://amzn.to/2svB3Qz

The Healthy Programmer, Kutner http://amzn.to/2qQ2MtQ

The Linux Programming Interface, Kerrisk http://amzn.to/2rsF8Xi

The Mythical Man-Month, Brooks http://amzn.to/2rt0dAR

The Practice of Programming, Kernighan and Pike http://amzn.to/2qTje0C

The Pragmatic Programmer, Hunt and Thomas http://amzn.to/2s9dlvS

The Psychology of Computer Programming, Weinberg http://amzn.to/2rsPypy

Transaction Processing: Concepts and Techniques, Gray and Reuter http://amzn.to/

Types and Programming Languages, Pierce http://amzn.to/2qT2d6G

Understanding MySQL Internals, Pachev http://amzn.to/2svXuFo

Working Effectively with Legacy Code, Feathers http://amzn.to/2sIr09R

Zen of graphics programming, Abrash http://amzn.to/2rKIW6Q

If you haven't, I highly recommend A Pattern Language. It's full of fascinating insights into the ways functional design interacts with our lives (and perhaps moreso, how dysfunctional design impedes it).

http://www.amazon.com/Pattern-Language-Buildings-Constructio...

I find this one more useful for residential building design, by the same author: http://www.iwritewordsgood.com/apl/set.htm

Available in hardcover on Amazon: http://www.amazon.com/Pattern-Language-Buildings-Constructio...

ATWoB is more philosophical, and lest about specific implementation.

APL includes nuggets along these lines: "Therefore: Make a public square much smaller than you would at first imagine; usually no more than 45 to 60 feet across, never more than 70 feet across. This applies only to its width in the short direction. In the long direction it can certainly be longer."

"When they have a choice, people will always gravitate to those rooms which have light on two sides, and leave the rooms which are lit only from one side unused and empty.[...]Therefore: Locate each room so that it has outdoor space outside it on at least two sides, and then place windows in these outdoor walls so that natural light falls into every room from more than one direction."

There are 253 patterns in the book, covering governed regions down to building wall details.

Read "A Pattern Language" by Christopher Alexander. http://www.amazon.com/Pattern-Language-Buildings-Constructio...

For me it's not even a programming book... which is what I felt the people who have answered have artificially limited themselves to.

For me, it's: http://www.amazon.co.uk/dp/0195019199

Pattern Language

It's about architecture, buildings, towns. How to make them work, to serve all the needs of them, and how to allow them to grow.

What is important to me and influenced me heavily is the thinking behind it. All parts of a large system in harmony, well-separated concerns, and working together to achieve a common goal.

In architecture (computer as well as construction), there is also politics. We pour ourselves into these systems, our beliefs come out in their design and implementation.

There was a lot that I learned from that book, and a lot that I still go back and refer to.

GOF took their inspiration here, it's obvious from the structure... perhaps you should see why?

Looks like a great book - adding it to my wish list. Thanks

(link to book on Amazon: http://www.amazon.com/Pattern-Language-Buildings-Constructio... )