We avoid I-95 through NYC and southern CT like the plague. Terrible roads, tolls, traffic and construction. I like the I-81 to I-84 route, although there has been construction on I-84 at the NY state border. Go north out of Hartford to pick up the Mass Pike. There goes directly into Boston, but with tunnels and underpasses going under large building, there are hazmat restrictions that include propane tanks. The Mass Pike crosses both outer rings (I-495 and I-95) that allow you to go north or south to any point around Boston.
It would help to know your exact destination.