There are lots of great roads in the area
My favourites are VT 100, VT 108, VT 118, VT 242, VT 105 from Jay to Richford, VT 14, VT 17 although it's in bad shape, and VT 102 along the Connecticut River.
In NH, 118, 112 (avoid on weekends and holidays) Bear Notch Rd, Hurricane Mt Rd, NH 113, NH 16, NH 135.
In Maine, ME 27, ME 182, Acadia Pk Loop Rd, Cadillac Mt Rd, RT 186 Schoodic loop, ME 126, ME 26, ME 16 From Errol NH to Eustis also in bad shape, RT 113 from east of Gorham on US 2.
Also check out this site:
https://www.newenglandriders.org/BestOfNorthEast/BestOfNorthEast.htm