Duffy’s has been a Holmes Beach institution since 1958, and its burgers are still pulling in commuters from Sarasota and Tampa, as well as long-time islanders and kids back home from college. The restaurant has added some frou-frou options like blue cheese, caramelized onions and the like, but its calling card remains its standard cheeseburger. The meat is the star, with a peppered exterior that delivers a sting. Ideal fuel for a day on the sand.