I live in the Berkshires, its a great place. Alot of country side, great for hunting, fishing, atv riding. Some years i dislike the long winters, but the long winters make you value spring, summer and fall. Im glad i was born here, even though the state laws are kind of over compensated.
Diversity of thought, culture, people and food. I have friends in the area from all over the world and only need to drive about 40 minutes tops to get any kind of food I want, experience great art and meet people from almost any part of the world. I also love the historical nature of this area. I live in a house older than your grandpappy.
Interesting question. Not so much limited to MA. What I love most is that we tend to have less problems (excessive weather, criminal activities, unemployment, etc.) than other areas in the country.
Proximity to everything. Mountains, beaches, and major cities (Boston, NYC) all within a few hours. Canada within a few more (as my Dad says, "Canada is almost like being in another country.")