Connecticut
Mystic Aquarium, Mystic Seaport, Mark Twain House, Gillette Castle, Biggest Casino's in the World, Go onboard the Nautilus sub at the Groton Navy Subbase, Coast Guard Academy,  CT Science Museum, many other museums. Two of the top ten food network Pizza houses in New Haven.

Massachusetts
Basketball Hall of Fame, Dr Suess exhibits in the Springfield Museums, Springfield Armory Museum, Old Sturbridge Village (1700's replication), Boston Aquarium, Fenway Park for a Red Sox game, Plymouth Plantation (early settlers village), Pilgrim Rock, Mayflower II , Provincetown Pilgrim Monument, Freedom trail, USS Constitution Museum, J.F.Kennedy Museum, Gay Head on Martha's Vineyard, Salem Witch Museum, Lexington and Concord Historic sites, Walden Pond, Lowell National Historic Park, New Bedford Whaling Museum, Six Flags Amusement Park

That's a very limited list of things to do in two states and doesn't cover all of the wonderful State Parks to visit...

New Hampshire:

North Conway Scenic RR. North Conway is also a nice town to walk around in.
Franconia Notch bike path
Mount Washington Cog Railroad

Maine:
Whale watching: First Chance whale Watch
Dessert of Maine
Portland Head Light
LLBean Freeport Flagship Store

NH

"The Flume" in Franconia
The "Kank" - incredible drive from Lincoln to Conway through the White Mountains.
Mount Washington - tallest point in eastern US and you can hike it, bike it, take a train up it or drive it!
The White Mountains
Tubing, canoeing or kayaking down the Pemi River - there are numerous campgrounds along this river that will take you upstream and drop you off.
Christa McAllufe planetarium - in Concord just off I-93
Robert Frost farm in Derry on Rt 28
Mount Monadnock - most climbed mountain in North America
The Lake Region - Laconia, Meredith and many other towns around several large fresh water lakes in central NH - great fishing, boating and swimming.

The kids might like:
Story Land
Six Gun City
Santa's Village
Clark's Trading Post
Lost River
Polar Caves
Ruggle's Mine

Lots and lots of shopping . . . . no sales tax in NH . . . . we make it up with the rooms and meals tax when you have dinner.  🙂

Lou, the Ole' Man caught the last train for the coast . . . . The day the music died.  :guitar:

Dang Lou, I've driven by the Cowbell Corners many times.  I didn't know it was called that!

I should have remembered the Bud plant . . . . I live 3 miles from it!  😮

Nice!  Thanks Dave!  :knuppel2:  . . . . . it's actually been 11 straight but who's counting.