I highly recommend a stop at Just Barb's for breakfast and for dinner. They have real corned beef hash, fresh blueberry muffins (made from scratch), blueberry pancakes packed full of fresh blueberries, and on and on. Dinner is worth the second trip for broiled full plate of haddock, or wild salmon, or all you can eat Alaskan Whitefish and chips, or Friday night Prime Rib, or any fried seafood of your choice. The only problem is it is really hard to save room for their delicious pies, strawberry shortcake or cake.
On Route 1 North, on the right hand side of the road a mile or so out of Bucksport on the way to Ellsworth, is (or at least I hope it is still there) a house with a hand made sign out front proclaiming home made pies for sale. They are indeed home made, and they are wonderful.
If you make it all the way to Ellsworth, try Helen's Restaurant, famous for their pies for many years. When I am in the area, I always make time for lunch at Helen's, and it almost always consists of a big bowl of excellent crab or lobster stew followed by a piece of freshly baked coconut cream, or banana cream, or wild Maine blueberry pie.
If you are traveling up the coast on Route 1 to get to Searsport, Moody's Diner in Waldoboro also serves mighty fine pie.
We lucked out this past July when we came across Just Barb's when the lobster cravings were getting bad as we were headed to Ellsworth. Unfortunately, we didn't leave room for pie. I would highly recommend her lobster roll, french fries and fried clams. Onion rings are fair but bland. Might have been different if we hadn't had three fried things at once. For steamed lobster, our most favorite place is Waterman's Beach. Drive past Owls Head Transportation Museum in Rockland and watch for signs. Wear a hat and sunglasses because the best tables are in front next to the water. There is a covered deck in back, however. This is lobster and pie territory. I went with Rhubard Pie and it was wonderful. I would also recommend the farmers market in Brunswick 9am-noon on Fridays. You can get a small blueberry pie from one of the bakers if a whole pie is too big. If you are cooking during your vacation, you can pick up most of your meal here. Some of the vendors also go to other markets.
If you like wine, don't miss a tasting at Cellar Door Winery in Lincolnville.
I always recommend Just Barb's in Stockton Springs, not because I've ever been there, but because I want to go so badly. Every time I go home to Maine, I swear I'll get to Barb's, but something always gets in the way. I've heard good things about the place for years. More than likely you'll drive right by it on your way Down East. If you give it a try, please report back!