Miami has long held a place in Americans’ imaginations as a great place to visit or live. A nationwide Zogby Interactive poll finds its appeal has faded, though. When people were asked which of eight big U.S. cities they’d pick for a vacation, Miami got 6 percent of the vote — well behind first-place San Francisco (19 percent). Just 3 percent chose Miami as the city to which they’d most like to move. Those Miami Vice reruns have left an impression: When people were asked to identify Miami’s important economic sectors, “illegal activities” ranked second only to tourism.