Chris' Camp in Spearfish SD is a great place to stay in the Black Hills. The CG is not big and fancy but it is clean, friendly and convenient. It is just off the highway (doesn't feel or sound like it is close to the highway however)and about 1/4 mile from the Spearfish Canyon scenic drive. We stayed there in the summer of 2008 and the owners were incredibly helpful. Very reasonable price too.
Another campgroundin Spearfish to addis Elk Horn Ridge RV resort. It's a new campground with a very nice ammenties. All roads are paved, sites are level concrete, 3 sewer hook ups (front, middle, rear), cable. The pool and hot tubs very nice. Bathhouses spotless. Playground for kids was great.
Negatives - Small trees little shade, no on site fires. They do however have communitee firepits (but who wants those).