Jimi - I apologize for the long gaps between writing. Things get so busy at work that I only think/get to stop in here once in a while. I have some free time tonight so I'm going to try to give you a few more bits of info. Looking back at my VT post, I realize it isn't as informative as I had wanted it to be. I didn't realize how uneducated I was about my surrounding New England states until I tried to sit down and type a thorough breakdown. It just goes to show that there are endless amounts of things to learn and places to explore. So my apologies ahead of time if I prove not to be as helpful as advertised!
While Vermont is my neighbor to the north, Connecticut is about twenty miles south. And, thanks to my employment in Hartford, I drive through it every day! Located right off of I-91 S and along the Connecticut River, Hartford is a city on the up. Millions of dollars have been poured into renovating old buildings, erecting a convention center, building a new grand hotel, condos, and eventually a science center. Despite these improvements, Hartford is still mainly a suitcase city. Once rush hour subsides, the streets are relatively quiet considering it is a capital city. But, I see this improving in the next few years as well.
Depending on your agenda and time constraints, I think Hartford would make a nice place to grab lunch and walk around. Take an hour off the road and walk around Bushnell Park with a sandwich or small meal from any one of many nice delis and restaurants in downtown. You could always walk by both the old and new state houses or visit Mark Twain's home and museum. Don't forget Hartford once was/possibly still is the Insurance Capital of the World! If nothing else, it has an impressive skyline.
I can't speak much for the rest of the state. There are many other large cities (New Haven - home to Yale U, Waterbury, New Britain, Bridgeport), but nothing that I know of that would cause you to seek them out on a national roadtrip. Of course, as you get closer to NYC, you hit some of the richest towns in the Northeast,if not the U.S. Greenwich's cost of living is far, far above the national average. Again, fun to drive through and catch an eyefull, but probably nothing you are going to put down as a main place of interest.
One last paragraph. It's been years since I went with my parents, but Mystic is very, very nice! There is a museum and aquarium, and the seaport is beautiful. If you appreciate fishing-town Americana, I think you'd love an afternoon in Mystic. Then again, you may want to go about an hour northeast of there to see one of the gems of the New England Coast. Stay tuned...