I went to National EMS Institute in Carver MA and did their 18-day boot camp. It's a bit of a hike, but the drive down from Boston is pleasant because you're going against the traffic. Justin Silva was the main instructor and he did a great job keeping things interesting, setting us up for real life and preparing us for the practical exam. Everyone in my class passed the practical very easily. I felt well-prepared for the written and passed on my first try.
All in all, I would go back and do it there again if I had to. They apparently have a boot camp starting tomorrow, and they have 24/7 support on their website if you want to talk to them: http://www.nationalemsinstitute.com/
I also went to National EMS Institute, graduated recently, and can stand behind everything J B says. If their 18 day program is a bit much, they also have several night courses. Overall great place, couldn't recommend it enough.