Ha ha, I feel bad that I teased you earlier so here is a real answer. I only interviewed at HMS, current students could tell you with more authority. The school is located in the Longwood Medical Area, which is a massive concentration of hospitals, graduate/professional schools, and research buildings. It feels like the medico-industrial complex set up its own compound a few miles outside downtown Boston. Some HMS students told me they take Uber to get to the more fun parts of the city; there's also public transportation except late on weeknights. There are some really nice neighborhoods not far from the school, including in the leafy independent city of Brookline. All of the nearby areas are expensive to very expensive to live in. I was told that 80% of first years and 50% of second years live in Vanderbilt Hall, which is across the street from campus.
It's worth noting that students do most or all of their third-year (changing to second-year in the latest New Pathway curriculum) clinical rotations at one of four affiliated hospitals, and some students move to live closer to the one they end up at. Beth Israel-Deaconess and Brigham & Women's are located in Longwood, Mass General is more downtown, and Cambridge Health Alliance is in fact in Cambridge.