If you do the I86 I88 route the scenery will be great. Lots of small towns but no BIG cities
You can stop at the Corning Glass museum
Cooperstown Baseball Hall of Fame as well as other attractions near Cooperstown.
US 2 near the top of Mass is an interesting ride if you do not mind a couple of steep grades and a couple of switchbacks. It used to be the main thoroughfare for Mass but now is relegated to second class status Some "Indian Trading Posts" on the route which are shtick but fun.
Otherwise I would take the MASS PIKE to 395 AKA 290 which will get you to 495 and you avoid getting real close to the Boston nuttiness 495 dumps you back on 95 just below the Mass Line. Stay on the NH toll road and get off the Maine 95 as soon as you are past Portsmouth and get on route 1.
There will be turn offs for Kennebunkport, Me and Boothbay