Belize, Belize, Belize. Specifically, Ambergris Caye, in the town of San Pedro. Seems like it would fit the bill- good nightlife, good food, relatively safe to walk the town at night, lots of live bands at the beach bars, etc, etc, etc. Many hotel choices to choose from... from the $30/nt range to a couple hundred. Would go back in a NY minute if I could- and plan on it in the near future.