We have lived in the Washington DC area most of our adult lives.
We stumbled across St. Mary's County in 2005 as we were looking for waterfront property (our must haves: within 2 hours of DC and no Bay Bridge traffic) and are so glad we did. We think the area is a hidden gem -- incredible waterfront, beautiful farmland, and a quaint town nearby, Leonardtown, which has one of the few remaining town squares from Maryland's provincial period.