The wife and I have been visiting a variety of east coast beaches over the last couple years. Here's my take on where we've been...
Rehoboth Beach / Bethany Beach (DE) - (relatively) short drive. Not too developed. We actually stayed in Dewey Beach which is between the two cities. Ocean City (MD) is a short drive south from Bethany for the full boardwalk experience. Assateague Island is cool (known for wild horses and mosquitos, LOL) and not too far away.
Duck/Outer Banks (NC) - not a bad drive. Duck is on the north end of OBX. We liked it and would go back. Not overly developed, but lots of smaller restaurants and stores. Kitty Hawk/Nags Head is a short drive south (middle of OBX) but much more commercial (think suburban mall sprawl) along the highway. Things get much less developed south of Nags Head. Wright Brothers museum is cool. If you have a truck (and a permit) you can drive up the beach on the north end of the island (north of Corolla). Wild horses up there too.
Topsail Island (NC) - another set of barrier islands to the south of OBX (north of Wilmington). Getting into a long drive now (10 hours from Pittsburgh). Lots of residential housing. Not much retail except for a few restaurants and shops in Surf City (middle of the island). Of course there is typical suburbia if you go inland a few miles. Really not much to do there except go to the beach or fish. We just got back from two weeks there.
North Myrtle Beach (SC) - Long ass drive. Ugh. Nice beach. Highly commercialized main highway but the road along the beach is a nicer mix. Had a fine time there and would go back. In fact, we were planning to go there this spring when COVID-19 hit. Maybe in the fall.
St. Simons Island (GA) - Really Long Ass drive. Did it in two days. Just north of the Florida line. Lots of mossy oaks. Firm sand on the beach (not my thing). Developed, but no overly so. We had a nice week, but would probably not go back (just for more variety).
Sanibel Island - Have to fly unless you want to do two long days in the car. We've been there twice. Awesome shelling if you're into that. Like, one of the best places in the world to look for shells. Nice beaches. Good selection of restaurants and shops but not over built. Would go back again for sure (wife loves shelling).
I would say that Sanibel Island was my favorite, but flying costs $$$ (plus rental car) and the Fort Myers airport can suck. But once there, it's very nice. For driveable spots, I would go back to Duck.
We are looking at visiting the Galveston area beaches next and maybe try to work the COTA MotoGP race (if it happens) into the mix. The northern Florida panhandle (Panama City, etc.) is also on the radar screen for a future visit.