Assateague Island & Chincoteague
Assateague Island is a barrier island located off the coasts of Maryland and Virginia - you can get out to Assateague through either state. The Maryland access is through Assateague Island National Seashore. You can camp there but there are no hotels or beach houses.
Virginia access to Assateague is by way of Chincoteague Island - another barrier island that sits between Assateague and the Virginia mainland. It's actually a series of steps to get out to Assateague. First you drive across a causeway that connects the mainland to Chincoteague Island. Once you hit the island you're right in the middle of all the hotels, rentals, restaurants, etc. You drive through the Chincoteague Isand resort area and across Chincoteague Inlet to get onto Assateague Island, but you're not quite at the beach yet. First you'll drive through Chincoteague National Wildlife Refuge - a destination in itself and part of the reason people choose to vacation on Chincoteague. Then, once you're through the refuge, you'll get to Assateague Beach. It sounds like a lot of driving but it's all actually pretty compact. It doesn't take all that long to get out to the beach and there's plenty of opportunity to spot ponies, deer, and birds of all types along the way.