I've used East Coast Areo Club based at Hanscom Field, Bedford KBED, to the North West of Boston. They have a wide range of aircraft and were helpful. An attraction for me is that you can get there from downtown Boston using public transport, avoiding both car rental and hotel car parking charges. Rates for the fleet are on their web site, but a C172 was $99 per hour.
http://www.eastcoastaeroclub.com/
http://www.airnav.com/airport/KBED
The downside is that Hanscom Field is run like Logan by Massport. It is therefore getting quite bureaucratic since 9/11 (remember where the hi-jackers boarded) and you will need to get a security pass. I didn't bother and just paid for an instructor - nice to have a guide and I let him do the radio work so I could enjoy myself. This is from their web site:
"Massport and the Transportation Security Administration have developed an ID Security Badge program for L. G. Hanscom Field. All students and renter pilots must have a Massport-issued SIDA badge for access to the aircraft ramp area. New students and those who don't have a badge will have to be escorted by a flight instructor until one is obtained.
Fingerprinting is done at the State Police office on the first floor of the Civil Air Terminal every Tuesday from 5-8 PM and on the first and third Wednesday of each month from 10 AM - 1 PM.
After fingerprinting, you will be notified when the background check is complete, and must then attend SIDA training before the badge can be issued. Interactive training sessions are conducted in Massport Management Office, Room 315 of the Civil Air Terminal, Monday through Friday 0900-1700. Call Airport Operations at 781-869-8000 to schedule."