I actually live in Charleston, SC and school and city is great!! It's a tourist city so beware of the costly homes and rental properties. I've been to the dental school here and it's absolutely incredible. MUSC is one of the top school in the country for surgeries and they have the latest technology in digital imaging for the dental school.
I don't know much about Howard, but I've heard that the DC area is freakin' awesome. Watch out for the swinger parties though... don't get caught up in that! ha