On James' Island, there's Folly Beach Brewing Company. It's technically a brewpub cause they serve their stuff + other great breweries. It's really small but really great.
I don't think they actually brew on premises, but there's a really neat place in downtown Greenville called Barley's Tap Room.
They have more beers on tap than your average hoitey toitey wine and beer store. As a beer snob, I am embarrassed to say that some of their taps are beers I've never heard of.
They have some VERY high grav things as well.
The whole place is decked out in wood which is quaint and comfortable. There's an upstairs bar for reserved get togethers with pool tables, darts, etc.
They also specialize in pizza. It's not the worlds best pizza, but it's pretty good for being outside Italy or Chicago.
I have not met anyone yet that doesn't speak highly of the place.