Ooh, I am in Western MA right now! (So, basically exits 1 and 2 on I90 in MA.) There's loads of fun things to do in the Berkshires, but here are a few of my favorites:
Tanglewood - summer home of the boston symphony, if you like classical music; next weekend is officially the end of the BSO season but they also do other shows here as well. Or just come some afternoon and enjoy the grounds/have a picnic. I don't think they allow dogs though. http://www.bso.org/brands/tang.....rview.aspx
Go to Bartlett's Apple Orchard for the best cider donuts EVER:
http://www.yelp.com/biz/bartletts-orchard-richmond
This is my favorite restaurant in the area. Totally a hidden gem. It's in the middle of a kind of abandoned looking industrial area, and you'd never know it was there. But the food is AMAZING and the restaurant is super cute. They don't take credit cards, and don't try to go without a reservation.
http://www.yelp.com/biz/elizabeths-pittsfield
There's loads of great hiking trails of all difficulties and lengths. I like mount greylock a lot - usually you can drive up to near the summit and do short trails around the top if you don't want to spend all day hiking. This site has trail maps for greylock and other areas:
http://www.bnrc.net/
There are many cute little towns to explore as well. I like Great Barrington a lot. I also like Williamstown, which is a little bit north from I90 and home of Williams College. The Clark Museum, which is great, is also located here.
http://www.clarkart.edu/