Spent many a night in Charleston; I would say:
Nice Restaurants;
Husk
Fig
Slightly North of Broad (SNOB)
Hominy Grill
There are hundreds of restaurants downtown though and it really depends on what you are in the mood for, the ones above are nice, but if you want more of a bar atmosphere, just walk around you can't miss them, as far as bars go;
Bars
Vendue Inn Rooftop Bar
Library - both of these are rooftop bars very nice (I think one of them wouldn't let me in with flip flops though... asshats)
Mad River Bar and Grill -in an old church
Market Street Saloon- sort of like Coyote Ugly, every chick is smoking hot and they dance on the bar a lot
Most of the Strip clubs are shady...they let you bring your own beer in I think, but lots of drunk soldiers around, with a large crowd, lots of fights breakout.