Abundance - Peter H. Diamandis, Steven Kotler. Diamandis has an almost infectiously positive way of looking at the world. And a hope that's not just based on a philosophical belief but is backed up with hard data.
Distrust That Particular Flavor - William Gibson. I never got into Gibson as a fiction writer, but this collection of essays, articles and talks immediately made me appreciate him as an amazing thinker, observer, and truly brilliant writer. This book is worthwhile for the pieces on Japan alone, but every single piece is wonderful.
Finite and Infinite Games - James Carse. An old book but one I only just discovered. No book has every so subtly had an impact on my life every day. The finite vs. infinite way of looking at the world has changed the way I think and act completely on the inside, yet it's probably hardly noticable on the outside. An amazingly easy book to read, couldn't recommend it highly enough.
How Music Works - David Byrne A unique and refreshing take on creating music that can be applied to the creation of anything. Byrne leaves the mysterious & ethereal world of 'creativity' for dead, and looks at how he creates music, and how the industry works, in a grounded and logical way. A brilliant book for anyone who creates anything.
The Plenitude: Creativity, Innovation, and Making Stuff - Rich Gold Another old(er) book, but one I can't believe I only just found. Rich Gold's outlook on how and why we make things should be required reading for anyone who plans on thrusting their big idea into the world.
Quiet: The Power of Introverts in a World That Can't Stop Talking - Susan Cain It's had a lot of press, but I'm going to recommend it anyway. HN undoubtedly has a higher than average number of introverts who truly operate in an extroverted world. This book was absolutely eye opening in how it deconstructs different situations and personalities in a useful and positive way. I wouldn't say it's 'changed my life', but it has made a few relationships with close friends and colleagues a lot better.
And a quick plug - for any avid Kindle readers out there, I've built a web app for viewing/sharing/organising Kindle highlights. If any HN'ers want early access sign up at http://kindred.it/ and I'll ping you a beta login.