Houston

HOUSTON, TEXAS: The fourth largest U.S. city, Houston is home to the world's largest concentration of health research institutions, NASA's Mission Control, an enormous theater district, two (yes, two) Chinatowns, a museum district that attracts 9 million visitors a year, more Fortune 500 company headquarters than any other U.S. city after New York, over 300 city parks, a team for every major professional sport, and more than 60 colleges, universities and degree-granting instutions. Not bad for a town that still doesn't have zoning.