GoFur,
We had a GREAT TIME at the Buffalo Chip Campground (you can see some of our pictures here Sturgis 2005 Pictures). they have all different types of campsites depending on what you want. You can be right in the heart of all the parties or go way off to a quiet campsite and ride or walk over to the action.
The main event area is great. The stage and field is surrounded by food and drink vendors including a couple of fun bars. The concerts were ALL great with plenty of room so you could stand right up by the stage or site in the back on a hill and enjoy the show without being crowded.
We didn't visit any of the other campgrounds like Glencoe, and Full Throttle didn't even have there campground open in 2005. I have heard that Glencoe is also a fun place and in the past few years they have improved their concert area and are getting some of the bigger names like the have over at the Chip.
Hope that helps you a little.