Lets see...
Amherst, MA:
Deathamphetamine (sick death/grind,
www.myspace.com/deathamphetamine)
Read Yellow (you've probably heard them)
Wasteland (hardcore)
Northern Aggression (bluegrass)
The Prowl (hardcore)
Boston (there are tons, here are some I like a lot):
Tommy and the Terrors (oi/hardcore)
For the Worse (hardcore)
Cut the Shit (wow, more hardcore)
Scissorfight (stoner metal)
Darkbuster (possibly the greatest punk band ever)
Agoraphobic Nosebleed (insane grind)
Toxic Narcotic (crust punk/hardcore/hateful as fuck)
Crash and Burn (punk 'n' roll)
Suicide File (great hardcore)
Slapshot (greater hardcore)
Blue Bloods (punk rock)
The Losing Kind (fucking great punk rock)
so many others...
Rhode Island/southeastern MA:
All Those Opposed (crusty hardcore,
www.myspace.com/allthoseopposed)
Dropdead (crust)
Lightning Bolt (you know them)
Doosh Bags (punk, think the Mentors or the Meatmen)
XFilesX (tongue in cheek straight edge hardcore)
Police Beat (thrashy hardcore)
Amazing Royal Crowns (now defunct, the greatest punkabilly band in history)
...
I go to school in Amherst and I'm originally from a small town halfway between Boston and Providence, RI, so I figure I have a right to list bands from many places.