Normandy beaches, north of Bayeux, Mont St Michael (small settlement on an island) and a day in the walled town of St Malo would be mine and the wife's recommendations.
We travelled south, stayed in Sarzeau for a bit which was nice, travelled on a small ferry across from Royan and stopped at Hourtin. Visit Lacanau-Ocean if you can (extremely busy though and packed full of buff surfing types of which i am not ). That sadly is as far south as we got as we only had two weeks.
At the time we had reduction boxes and thought the motorway would be the better route to travel, it wasnt. If you can stick to the A roads as they are usually much quieter and lovely to drive along. Far superior roads over there IMHO.
Most small towns have municipal campsites (brown signs I think) and they are ususally good quality and cheap (certainly recommended for single night stop overs).
Starting to waffle a bit now but it is a lovely country to go in a bus.