nostrademons

Pragmatic Programmer by...well, it's mentioned elsewhere here.

Anyone who has to manage a team of programmers and hasn't read this will fail utterly, unless they've already failed before (or been on a failing team). There's a lot that's counterintuitive about software project management.

Crossing the Chasm is mostly useful as a reality check for startup founders

Crossing the Chasm by Geoffrey Moore

#1 for me would be The Intelligent Investor, by Benjamin Graham.

Innovator's Dilemma and Innovator's Solution by Clayton Christensen

Built to Last and Good to Great by Jim Collins.

The Tipping Point by Malcolm Gladwell

I like this better than Purple Cow, Guerilla Marketer's Handbook, and The Big Red Fez.

Built to Last is more applicable for startups.

Innovator's Dilemma and Innovator's Solution by Clayton Christensen

which is a good book

Building Scalable Websites by Cal Henderson