A report from our family Nantucket trip -
Breakfast: Black-Eyed Susans - excellent, fresh, well prepared food in a cozy setting. Highly recommend!
Lunch: Summer Place in Scionset - nice outdoor location with a "St Barts" feel and prices. All entrees/sandwiches are above $15 and the food is pretty average. Expect to spend $30+/person.
Fog Island Cafe - great variety and tasty food including sandwiches,wraps, salads - reasonably priced.
Dinner: Arno's - good food right on Main St. Pastas, quesadillas, burgers, etc. Not expensive for Nantucket for a good solid meal.
Vincent's: Again fresh, well prepared basic Italian dishes in a comfortable dining room. Good family restaurant.
Black Angus Grill: their specialty is steaks which were excellent. The sides are a la carte and very average.
The location is mid-island - the patio is outdoors, by the road.
Hope this helps - especially family travelers.