It appears to be Burlington, Vermont. (Hi Margo!)
"It's among the best in exercise and among the lowest in obesity, diabetes and other measures of ill health, according to a recent report from the U.S. Centers for Disease Control and Prevention." says CNN.com
How could it get any better? Jet Blue (my favorite airline, like EVER) flies there.
FYI: Huntington, West Virginia is the unhealthiest.