How about your favorite beach? Want some peace and quiet but not dull. Don't mind driving 4-5 hours. Are there cottages to rent? Is that easier than a hotel?
Looking for beautiful sand

Have you been to the Washington Post's travel page? They run profiles of the most popular nearby beaches each summer. www.washingtonpost.com

North Carolina's Outer Banks. Rental cottages/nice sand/good restaurants & bars. Consider Corolla, Duck, Kitty Hawk, Nags Head...any of the areas. Much quieter than OC Maryland.

Another choice might be OC New Jersey. Same ammenities as the Outer Banks, but a boardwalk (if you choose to partake). OC NJ beaches require a beach pass ($$), but most of the rental cottages have them for their guests. The areas away from the boardwalk can be peaceful and quiet.

Cape May is a beautiful, quaint, victorian beach town. Its more expensive than the rest but worth a try. Check out http://www.capemay.com for a great web site.

I second the recommendation for the NC Outer Banks. I can't say its a lively place, but there is a lot to see and do. You can fish, see many beautiful lighthouses, shop, sailboard, visit aquariums, visit the site where the Wright Brothers first flew, etc.