My long run used to be from Park Slope down third avenue and second avenue, through Owls Head Park to the Belt Parkway to the Boardwalk and back up Ocean Parkway to Prospect Park. It breaks up the monotony of six laps of the park. The first stretch through industrial Sunset Park might be a little desolate for your taste, but at least traffic is light. And running by the water, under the VZ Bridge, along the boardwalk, and up the grass median on Ocean Parkway makes up for it.

I also sometimes ran from work in lower Manhattan. When coming over the bridge, instead of dealing with the traffic and exhaust in Downtown Brooklyn, I would double back down to Furman Street, under the Brooklyn Heights esplanade. This becomes Columbia Street, and you can take it all the way past the Battery Tunnel entrance before looping back up through Red Hook and up Ninth Street to Park Slope.

Enjoy!