A thriving university town with one of the best live music scenes in the country, Austin's youthful, creative vibe keeps people coming.

With it's more than 250 live music venues and festivals like its famed South by Southwest (or SXSW) Austin's "cultural vibrancy helps to drive the economy in a big way," said demographer Ryan Robinson.

Another driver: Jobs.

Austin's massive University of Texas, with its 50,000-plus enrollment, is known for its engineering and computer science programs, which have spawned many local tech businesses and incubators. It has also attracted a number of big tech companies -- Apple (AAPL), Google (GOOAV), Facebook (FB), Intel (INTC) -- looking to recruit young talent.

In January, the city's unemployment rate fell to 4.7%, the lowest of any metro area with a population of one million or more.