And Boston Fire and EMS are conventional, with the TGs patched, so as such, the audio is better on the analog channels.
Scanner Frequencies and Radio Frequency Reference for Suffolk County, Massachusetts (MA)
www.radioreference.com
Two other suggestions not mentioned here:
You'll want to throw in Mass State Police, H-PTL-1 and Statewide. H-PTL-1 patrols the immediate Boston area and you'll hear some crazy stuff on there sometimes. Statewide is used by the Helicopter more than anything, and you'll hear it go to big calls sometimes throughout the Commonwealth.
The other one you want is BAPERN, our intercity radio system. Also conventional with patches to the trunk.
Scanner Frequencies and Radio Frequency Reference for Boston Area Police Emergency Radio Network (BAPERN) (Massachusetts)
www.radioreference.com
Specifically BAPERN 3 and 4 are going to give you probably the most traffic as well.