Optimize for Happiness - Tom Preston-Werner →
Tom Preston-Werner, presently the CEO of GitHub and one of its three co-founders, gave a talk at Startup School (from Y Combinator) in 2010. He discusses the importance of optimizing a company for happiness, as the happiest employees produce the most value both for the company and for the employee.
There is an interesting 25-minute talk as well as the post to which this posting refers.