I recently had a nice experience in Charleston. The Ellis Creek Bistro is a small place at 807 Folly Road (on James Island). It has less than twenty tables, so call for a reservation (843.795.3838).
I had a piece of Red Snapper that was perfect. Someone else had a piece of Salmon that was excellent as well. The prices are in the moderate to moderately high range (mid to high teens for an entree). The wine list is adequate, and not overpriced (1.5 to 2 times retail).
Also ate at The Boathouse on Isle of Palms. It was good, but not remarkable