Charleston-Savannah --local joints
As a local Charleston Foodie/Chow Hound here are my "Really Really Local" recomendations in the Holy City. These are in no particular order, but all are sure to please if REAL REAL LowCountry food is what you want.
The Stono Market Cafe - Maybank Hwy - Johns Island (BTW I live on Johns Is and this place is great!)
The Mustard Seed - Maybank Hwy -James Island
Mondo's Delight - Folly Rd- James Island
The St. Johns Cafe - Brunch on Sundays is the best (Crabcakes benidict will make you want to"Slap yo daddy"
Bowen's Island - Oysters roasted over open fire (IN THE BUILDING!!!) wear real "don't care if I have to throw them away" clothes, the smoke from the fire gets intense.
THat should hold you for a few days. Remember you probably won't see any other NYC types there, but I gather that is what you are looking for!!
In Savannah, I'd suggest Crystal Beer Parlor, Mrs Wilkes' Boarding House, Elizabeth's on 37th, and Wall's BBQ. Elizabeth's is upscale and pricey but has always been worth it every time I've been there. Crystal Beer Parlor is an institution; Johnny Mercer used to frequent the place in the old days - great oyster sandwiches but the crab stew may be overrated. Mrs. Wilkes' is well-known and often the subject of write-ups, however, many seem to prefer The Lady & Sons which offers similar dishes (I've not been there myself). Wall's BBQ is the best downtown barbecue, although many Savannahians still prefer Johnny Harris on Victory Drive, which has great sauce - get some and also some Benne Wafers while in town.
In Charleston, I'd wholeheartedly recommend Jestine's Kitchen and Hank's Seafood. Hank's isn't cheap but I thoroughly enjoyed it. Jestine's is a steal and great for lunch. Louis Osteen's place and Peninsula Grill also get rave reviews, as does Anson's, but I haven't had a chance to visit any of them yet. Thought Magnolia's was somewhat disappointing when I was there two years ago but I had a nice time at Poogan's Porch.
Hope these suggestions are helpful and that you enjoy your trip.
We had a delicious lunch at The Lady and Sons in downtown Savannah. Opted for the buffet lunch and I remember most the multitude of wonderful sides--really, really rich mac and cheese, fried eggplant, the best collards I've ever had (piqued with a pepper/vinegar sauce that's on each table), superb hot biscuits and corncakes circulated through the dining room as they came out of the oven. Mounds of fried chicken. I was sorry I didn't have two stomachs to keep packing it it... Loved it--even bought the cookbook, which is very much a basic community recipe book effort.