A few tips on and around Deer Isle. Hardly a chowhound mecca, but there are a couple of spots worth knowing about if you happen to find yourself there, though nothing worth going out of your way for.
Fried fish (haddock) sandwich is probably the best thing to eat on the cheap. The Fishnet in Blue Hill does them well (also very good lobster roll here). Ditto for the Country View (which has a pretty view indeed) about three or four miles south of Blue Hill on Route 15. The offerings on Deer Isle itself are less satisfying. The Fisherman's Friend up the hill in Stonington does an okay fried fish sandwich or plate (I'd have to disagree with a recent posting exalting this place - it's warm and friendly, but the food is pedestrian). On Stonington's main street, the Harbor Café's version is greasy (also in evidence at breakfast time - better to stay away from the hash browns). One place I haven't tried for fish sandwiches is Conni's, a bit farther out of town from Fisherman's Friend, which attracts a mostly local crowd. It has the best breakfasts, though, with cakey homemade donuts as the main attraction.
Much to be lamented is the loss in Stonington of Blake's, behind Bartlett's Market. They did a terrific sandwich, light and crisp (and cheap). Alas, Bartlett's was sold last winter to some Floridians, and apparently Blake's was part of the deal. Although it's still open (as The Take Out), they don't even make fish sandwiches any longer, now only burgers and ice cream.
Speaking of ice cream in Stonington, the ice cream stand on main street is back to something fairly good after last summer's Edy's interlude. It's homemade again, with some interesting flavors, like black raspberry; but it's still nowhere near as good as it was when Woody was making it three and four years ago (aka "The Cranberry Tiger") - some of the best ice cream I ever had (think a more custardy version of Ciao Bella or Cones, with the flavor explosion), and he would practically give it away. For a reason - he was making much more money dealing dope, and his reign ended with a prison term.
For non-Maine offerings (and the Maine stuff does get boring pretty quickly), Lily's is the best in the less expensive range. At the edge of Stonington (more than a walk), in a big old cozy house, Lily's has a range of sandwiches for lunch and dinner, and always a couple of dinner specials. Last summer I had a quite excellent pork loin, this year a satisfying (if somewhat under-spiced) chicken tetrazzini. (Stay away from the fish sandwich here - it's baked, and just doesn't stand up if you've been eating lots of the fried ones). Excellent desserts, friendly service, everything under ten dollars. Remember to bring beer or wine. Closed weekends. (The only place on the island that has a liquor license is Maggie's, whose sign promises "lousy food and warm beer" - and delivers on the former, at least.)
For more expensive stuff, there is the Goose Cove Lodge. I have only been there for Sunday's buffet (last year), which is worth whatever it is they charge (I think in the $20-25 range). Unlike most buffets, with all the wilting or curdling or seeping of juices, Goose Cove has seatings, so that everyone starts at basically the same time, and everything is eaten basically as it is prepared. It's good stuff. (Reservations a must.) I'm sure dinner is good, too, but not cheap, and I never understood the point of fine dining when the whole idea of going to a place like Maine is to rough it a bit. Blue Hill also has some more expensive restaurants, from appearances none of which seem worth the trouble.