I'd endorse all the comments about Eurocamp etc and the Dordogne - excellent choices. If the Dordogne is too far (though it is motorway all the way to within about 30 miles of Sarlat these days, not like when I were a lad...) then Alsace is an interesting place to visit (around Strasbourg). Some parts of the Loire are also good, but in general the northern part of France, around the Pas de Calais, is for driving through as swiflty as poss.
Other thoughts - the Ardeche or the Gorge du Tarn are stunning - the latter takes you on/near the Millau bridge - sorry, I can't manage the technology for posting a piccie, but google it and be amazed...
btw I've always found the Michelin green guides are extremely reliable, and in some of these locations you can do a whole holiday of 3* sights.