You should check out the Kentlands in Gaithersburg, MD:
http://www.kentlandsusa.com/outside_home.asp
From what you describe it may fit the bill. It's a shop and live community. Although in the suburb of Gaithersburg you can walk to all the shopping you would need, including grocery, home improvement, restaurants, movie theater, lots of specialty shops. The housing is town house style.

It's a bit of a hike into DC, if that's your criteria, 20-25mi. But you could take the Redline metro which isn't too far away, about 7mi & mostly I-370.

And there is easy access to more rural haunts that others mentioned, like the Poolesville area (11mi away), where the biking is awesome: traffic is light, scenary is great. If you're a climber, Sugarloaf mountain isn't too far, 15mi away. And Seneca state park has great off-road trails, only 5mi away.

I don't live there so I'm not self-interested. Just know of it as fitting your description quite well.