Boston, Cambridge, and surrounding areas are an excellent place to ride a bicycle (in my opinion). It's relatively flat, everything is close, and the traffic is congested so it's easy to keep up.
Boston drivers (and cyclists) are aggressive, but predictably so. There's only about one mile's worth of bike lanes in the entire city of Boston, but who needs 'em? One can get by just fine without them (though I understand that bike lanes might be useful in other locales).
I also think that since the streets are not laid out in a grid (except for Southie and parts of the Back Bay), it makes it more interesting to travel around the city. Every street and every intersection is unique.
Boston has a worse reputation than it deserves.