I grew up in Belmont and loved it. I'd go back in a heart beat. So envy you, OP. My family/friends who are happiest with public schools live in Cambridge, Sherborn, and Hingham. That doesn't mean those are the best schools, of course, just that those folks have found what they value in the schools. The Cambridge family probably values diversity most, the Sherborn folks are very intent on academic excellence and rigor -- though they also complain about competitive culture, and the Hingham folks are pretty mellow (tipping my hat to you, cousin C

).
Good luck, OP!