Why anyone would go to KFC or Burger King in St. Martin is beyond me...don't they get enough of that junk at home?
Go to Grand Case (French Side) - they have barbecue restaurants at the beach that are casual and the food is very good. Orient beach also has some great restuarants and the beach is fabulous.
The best way to see the island is to rent a car/jeep and just explore. Don't even think about renting scooters as the roads aren't great and there are lots of hills.