Boston is a VERY modern community (too liberal for me, actually- politically, that is).
Baltimore, OTOH, is cheap, and has a nice mix of demographics- plenty of yeshivos (although they don’t have much of a frum MO day school; Beth Tfiloh is a community day school, and the other schools are very frum), R’ Berger’s shul has great learning, Ner Tamid, Suburban Orthodox, Netivot Shalom are all great shuls.
Long Island has communities like West Hempstead, Plainview, etc. that are nice, but may not be too affordable.