Lots of wealthy people would disagree with this, but I gotta say - I know a few pretty rich folk and they really aren't any happier than less-heeled people; they have more opportunity and more stuff, but it doesn't seem to feel the hole:
Of all the important and interesting findings Dr. Kahneman and Dr. Deaton's research has uncovered, the most reported finding is that people with an annual household income of $75,000 are about as happy as anyone gets.
Then, I found this interesting - italics are mine:
A key stumbling block is that Parmar is seeking a percentage of any savings he finds as compensation. He’s also said he would accept payment in the form of a government appointment or increased provincial funding to fight ovarian cancer.
Here's a guy that's found the secret; offer value, but don't just seek more stuff in return - gain in terms of self-satisfaction and personal brand by giving value back.
Don Drummond provides a great example of this kind of thinking, which I believe we'll be seeing more of.