Redfeather Roleplaying is good people. The playerbase is located largely in the Cambridge/Somerville area and out towards Springfield. They currently have 3 active games, which I will describe (badly for brevity) as etherpunk in the age of sail, traditional fantasy-adventure in the woods, and magitech on a traveling city. Crappy placeholder website here.

I'm not sure if Romancing Jan is still running, but keep an eye on Incantrix Productions and Rainbow Unicorn Games for inclusive and queer-friendly events with high production values.

Club Drosselmeyer is a theater dinner semi-larp sort of thing that runs every December, and is great fun.

You can also connect with more nerds at places like Athena School of Arms, Knight Moves Cafe, Pandemonium Games, and Comicazi books and games.

Probably several places I'm missing, but that's off the top of my head. Happy to go into more detail about any of them.