If you want just straight seafood, go to one of the places on the beach that have the word "seafood" in their name. If you want some seafood cooked more delicately, I would suggest two restaurants...
1) Waterscapes at the Marina Inn - chef James Clark does some really fantastic stuff with fresh local seafood (he almost feels bad sometimes if he gets fish from Virginia because it is too far away) he is one of the leaders of sustainable local seafood in this area
2) Carriage House at Litchfield Plantation (Pawleys Island) - chef Rob Beuth is right up there as well, ahving the benefit of being so close to where the fish come in on the docks, he actually goes there himself to pick it up (most 'fresh' fish gets cought here, shipped to Atlanta or Charlotte, is bought by local restaurants and shipped back, pretty stupid)
You wont find your fried flounder and broiled seafood platter at these two restaurants, but rest assured that the seafood will be local and prepared in a more thoughtful and gourmet manner.
Right now most restaurants are serving local shrimp and seafood with the exception of the chain restaurants because it is so cheap.
Go to Murrells Inlet: Russells, Divine Fish House, Bovine's, Prossers BBQ, Creek Ratz, Davids, Dead Dog, Hot Fish Club, Inlet Crab, Oliver's Lodge.
Oh, go to Lee's in Murrell's Inlet! Lee's Inlet Kitchen is owned & run by the same family that opened it back in the 50's. Their shrimp and scollops are great, fish is fresh, and their onion strings are to die for. Manhattan clam chowder is also good. Have heard Oliver's Lodge is good, but haven't made it there yet. We did try Drunken Jack's in Murrell's Inlet on our trip last week and were a disappointed - just not the quality that I remember from other trips.
We had a nice lunch at Capt Dave's in Murrel's Inlet yesterday. Nothing fancy but great views. I had a fish sandwich that was very fresh and done perfectly. Big bowl of crab soup that was tasty but a little thick for my taste. Oysters on the 1/2 shell were very good.
Drunken Jack's was right next door.
We passed Prosser's BBQ and it was busy at lunchtime. Would have like to try it but I was with my parents and they were bbq/roadside dining'd out..:)