Good- generally the further north you get the better it is- with the exception of the coast of Maine. I'd suggest including Burlington Vt- great food town. The drive up RT 100 from Wilmington to the north country is scenic and will take you though some typical VT villages. There are some really scenic notches further north.
NH is wonderful, from the lake's region into the White Mountains- Franconia Notch and Crawford Notch are nice drives, the Cog Railway on Mt Washington or the Crawford Notch train out of N, Conway are memorable- and Lake Winnipesaukee is nice as well. If you want to avoid crowds, N. Conway may not be your cup of tea. We generally use Lincoln NH as our base when in NH.
Maine- what is there to say? Lakes, mountains and the seacoast- it's all good. The Rangely Lakes and even more so the Moosehead Lake areas are less traveled. Bar Harbor and Camden are lovely but full of tourists. I'd go further up the coast given time- but you can't go wrong anywhere.