Maine
DITTO...Kebo Valley is a real treat. Worked a summer after college in Bar Harbor and spent probably 20 of my perfect Maine Coast summer evenings playing there. Very old school with some history (at some point said to be the 8th oldest course in the US). I think the first four holes in the valley in front of the clubhouse are very underrated and another nice stretch from 8-10. Doak gave it a 4 (although in one of his lists it is a 5 which is more accurate for me if not a 6 on his scale). Great little greensites with some driveable par 4's and #17, a very unique hole (a New England version of #2 at Pine Valley). Play 36 in one day and walk. Kebo plays beautifully when a little dry and gets some wind.
Northeast Harbor, also on Mt. Desert Island, is a neat little track at just over 5,500 yards with some really fun holes.
Wawenock is a lovely little 9-hole round that I've never heard anyone else talk about and is very much off the beaten path. Very interesting fun holes - favorites are 1 & 2, 5, and 6 which very much reminds me of Merion's famous 11th, while 7 and 8 are wonderful uphil holes to neat greens. Well worth a trip around for $20.
If you can get on Portland CC or Cape Arundel in Kennebunk; PCC is an interesting Ross track with some great holes on the back nine and CA is an old Travis par-69 short on yardage but looks to have some character (have not played but walked some of the property).
New Hampshire
Mt. Washington Course at the Omni Resort is an old Ross layout restored by Silva that has a great deal of charm and in the fall would be a truly great day of golf.
Vermont
Yes...Ekwanok is outstanding!
But, don't pass up Rutland where Bobby Locke played a good deal of summer golf and Bob Rotella grew up caddying. RCC is a Stiles/van Kleek gem that is just over 6100 yards with a stern par of 70 (would be a better 69 like Rye) and is full of variety and fun - highly recommended.
Burlington CC is a Ross that has been redone and is worth a bit of effort to get on.
Vermont National is the first Nicklaus design in New England and one of his more playable designs...but, not nearly as fun as Ekwanok or Rutland.