The best region that you haven't tried would be Cambridge, which (i) is a very close and cheap taxi ride, (ii) has mostly hotels that are close enough to T stops to make it a very easy trip (often about 6 minutes on the Red Line to Park St.), and (iii) has mostly hotels that are in fairly interesting areas of their own. Second best, in my opinion, would be Brookline/Newton. Newton is boring but you can take the T downtown, easy and cheap; Brookline has some interesting areas of its own and you could actually walk from some parts to some tourist sights (Fenway Park, even the Museum of Fine Art or Back Bay). Medford/Somerville Hotwire has what appears to be the Hyatt Place; that hotel is not close to the T, unfortunately, so public transportation would be possible (bus) but not very convenient; still, it has free parking. You can go further out, and some of the outer suburbs have okay light rail connections -- look for what the MBTA calls the Purple Line, but this is a quite different system from the rest of the T. (A bit like Metra in Chicago.) Quincy has Red Line access, it's just a longish ride (30 minutes or so). I have to say that I do *not* recommend driving into Boston in the summer. Besides the cost of parking downtown, it's a drag, the traffic is bad, and driving downtown is very confusing, much more so than New York or Chicago. If you stay south or west, you can drive to a park-and-ride station and take the T in, and I would really recommend doing that instead.