As far as New England is concerned, Acadia National Park is a must in our books. We stayed at Bar Harbor Campground while visiting the park. We liked it so much, we stayed twice as long as we had planned. Shore Hills Campground in Boothbay, ME, was also a very enjoyable visit. Lots of great sightseeing in both places. My wife went to graduate school (the second time) in Vermont and I really enjoyed seeing the campus in Middlebury, VT. We did a lot of back roads and out-of-the-way campgrounds. Didn't have ANY negative experiences and everything was beautiful - despite the fact that last fall was a "low color" fall as far as the foliage was concerned.
Rob