Quality of camp sites varies all over France, in that you'll get sites of different standards in every part. It depends on your budget (Doesn't everything?). Most, if not all, local authorities run their own sites, usually known as 'municipal' camp sites. These are basic, but clean and cheap.
On the other end of the scale, you have the Les Castels chain, most of which are, or used to be, based in the grounds of chateaux. Have a look at
http://www.les-castels.com/en/
Don't know if that helps...