One of only two functional drive-ins in South Carolina [1], the Highway 21 Drive In (55 Parker Dr., 843/846-4500, www.hwy21drivein.com [2]) has two screens, great sound, and awesome concessions including Angus beef hamburgers. All you need to provide is the car and the company.
The best multiplex in the area is the cool Sea Turtle Cinemas (106 Buckwalter Pkwy., 843/706-2888, www.seaturtlecinemas.com [3]) in the Berkeley Place shopping center.
Links:
[1] http://www.moon.com/destinations/south-carolina
[2] http://www.hwy21drivein.com
[3] http://www.seaturtlecinemas.com