1. Change of seasons (although I'm liking winter less and less).
2. Just a hours away (or less) from mountains, lakes, seashore, city activities in Boston & NYC. The mountains/ lakes & seashores in VT, NH, ME, RI, CT & NY offer a wide range of activities and sites to see all year round.
3. Great hospitals, colleges, culture, history, restaurants, museums, etc.
Of course there are plenty of downsides to MA as well, but overall, once you get outside Boston, for the most part, New England is a great place.