Being a Bostonian myself, I'd say come here (w00t!), but it's hard to say.
The best way to make the decision is to visit a campus and meet the people. I'd say you can't go too wrong with MIT *or* Stanford for robotics. Both have really incredible programs (though from my own knowledge, I think Stanford is significantly more EE/CSy focused... MIT is very strong there, but also has stuff for the MechE folks as well, so there's more opportunity for interdisciplinary collaboration). Besides, wherever you don't go for undergrad, you can always go for graduate school.
If you can't make it to either campus, do you know anyone from either school? Can you find them online to talk? Can you find blogs from folks at those schools? How happy do they seem? What do they talk about doing in their free time? I think that'll help you.