Over the past decade or so, Denver, Boulder and the surrounding region have developed a well-desreved reputation as one of the nation's very best places to live. That's important because people today increasingly get to choose where to live. Some 40 million Americans move each year, and 15 million of us make a significant move - to another county, another state or another country.

In fact, the place we choose to live is the most important decision we ever make - largely because it influences and shapes all the other decisions - from the job opportunities and career options that are open to us, to our investments, and the friends we are able to make, the people we date and the mates we ultimately choose, and the way we raise our families.

The greater Denver metropolitan area scores highly on a new set of rankings my team and I compiled based on the five major stages of your life. Denver itself ranks in the Top 10 places for young professionals. And Boulder ranks in the Top 5 smaller regions for single college grads, young professionals, familes with children and empty-nesters.

There are several reasons underpinning the region's consistent high marks. In a survey I conducted with the Gallup Organization we found that, alongside your job and personal life, the place where you live factors greatly in your happiness. Denver is one of the few regions, along with Austin, Texas, that scores high across all three of these key happiness factors.

The survey also pinpointed five key factors that make people happy with their communities. Great places get the basics right - they have great schools, good roads and public transportation. Then there's physical and economic security to consider - crime rates, public safety and job opportunities. The quality of an area's civic and business leadership is important as well. Denver does well in all three, but the community is off the chart on leadership.

Mayor John Hickenlooper's nonideological, post-partisan style has won him accolades across the country, including being named as one of the nation's best mayors by Time magazine. Our survey shows that Denver residents see it as one of the best-led places on the planet. And not just in politics - the region's business leadership scores high marks as well.

Another key is openness to different kinds of people. Our survey asked some 28,000 Americans across every possible demographic category a question: "How would you rate your city as a place to live for the following kinds of people: Families with children, racial and ethnic minorities, gays and lesbians, immigrants, seniors, people living below poverty, young singles, and recent college graduates looking for work?"

With every degree of tolerance extended to these groups, the overall happiness of the community increased! Not because we value diversity as an abstract value, but because many people are drawn to open communities on the assumption that these are places where they can be themselves. The region scores highly for young professionals, and Boulder ranks in the Top 5 for young gay singles.

The survey also found that the higher people rate the quality and beauty of their community, the higher their happiness. This is a huge advantage - it's the major reason people choose to move to the region to begin with.

But there is an even bigger economic factor that bodes well for the region's fortunes. With nearly 4 million people and $140 billion in economic activity, it ranks as one of the top dozen mega-regions in the United States. In fact, it's one of the 40 leading mega-regions that power the entire global economy.

These 40 megas, which make up just 17 percent of global population, account for two-thirds of its economic activity and more than 90 percent of global innovation. Far from being flat, the world economy takes shape around these spikes of economic activity and innovation.

From New York to London, Tokyo to Shanghai, these mega-regions are the ones that pull in talent and generate the ideas which drive the world economy forward. And Coloradans can count Denver-Boulder as one of them.

Richard Florida is the author of Who's Your City? (published this month by Basic Books, whosyourcity.com) and director of the Martin Prosperity Institute at the University of Toronto's Rotman School of Management.