I lived out there for a little bit, but that was about 6 years ago, so things are a bit rusty. I'm sure there are others who can weigh in that might be more helpful. I also didn't have a motorcycle out there. I do seem to remember enjoying some drives north of DC, South of Baltimore, West of 95 all the way over to near the Potomac. Can't speak to how twisty they are, but there were some nice country side kind of drives.
I also vividly remember a beautiful drive to Charlottesville along some of the smaller backroads during the Fall. Beautiful. There's lots of great stuff beginning just 30 minutes or so out of DC. I'm not sure how helpful this is, but perhaps it gives you some ideas of where to begin. You can always just look at google maps and identify the twisty roads...
You're making me miss the area out there...
Have fun exploring!
2011 Imperial Red
Givi V46 / V35's SW Motech mounts
Skidmarx hugger Moto Werks bar riser
Mondo Motors LED Driving Lights
A little bit of road rash