We went to Brittany last year and satyed in baden in a gorgeous campsite called Mane Guernehue - it was fab and a short walk into the village (had arestaurant, butchers, bakers, PO etc). Not near a beach though but on Golfe de Morbihan so plenty of choiuce if you don't mind driving. We're off to Brittany again this year to le Guilvenec - Camping Vialllage la PLage which is right on the beach. Sounds like it's pretty near town too.
I'm sure there was 1 campsite in the French Life brochure which was close to a town centre and another one where you got the water taxi from the campsite to the town but I can't remeber where (probably not even FL knowing me!!) Why don't you pick where you want to go (UK or France) then scour the websites for a campsite with everything you want then book direct. Try www.matthewsfrance.co.uk click on a location at the top (anyone, such as 1Vendee1) down near the bottom of the drop down menu you'll find the message board - it's a fab discussion forum where you can post questions and someown will know the answer!
Have just got back from Stiffkey in Norfolk - really lovely. You can walk to the sea but it is a trek across marshy ground. You can drive to Holkham or Wells-next-the-sea which are lovely sandy beaches.
Was recommended to me by another mumsnetter so feel I have to pass it on!
The village is small but nice and the facilities at the campsite are simple but all we wanted (showers and washing up sinks).
This is a good family site in Dorset.WarehamForestTouristPark We camped so stayed in the free camping area which was very friendly in the evening with children playing together. Well organised and neat. You can never guarantee the noise level but we stayed in the Summer holiday and it was very family friendly. It isn't in walking distance of the beach or town but it is a good base for visiting Dorset.
Agree with Cupcake that Norfolk is gorgeus. We've just been staying in Happisburgh and spent a couple of days at *Sea Palling* (between Yarmouth & Cromer). Sea P has a caravan site that is about 300 yards from a great sandy beach and between the site & the beach there is a fantastic kids' playground & a pub that does food.
There's not much of a town there but depends what you want. If your kids are small and you want a quiet easy holiday it's great. If you want more entertainment close at hand, pehaps not.
PS - Nearby things to do include steam trains, boat trips, farm parks & Norwich is about 20 miles.