We stayed in a mobile home in Les Ecureils last summer. It's a lovely little campsite just across the road from the beach. The pitches the mobile homes were on were very small and so now that we have decided to camp in our own tent next year I've been looking for sites with larger pitches and, in the main, these seem to be the ones further in from the coast. There's also quite a lot of noise in the evening from the attractions further along the road in St Gilles and so I'd prefer something a little quieter. I'm torn between Le Pin Parasol and La Garangeoire - both have great reviews and large pitches and as hubby bought an inflatable canoe yesterday its great that they are both near Lac du Jaunay.
Not been to those two but have been to La Garangeoire. We Booker this for the reasons above, coastal sites can be so noisey. This one is close to the beach by car and it nice and quiet. Large pitches and plenty of space for the children to kick a ball about.
Have you considered Le Zagarella at Longevillle ? Great plughole slide, indoor pool, water play area for smaller kids, plus outdoor pool with slide. This one is a France Loc site so very French but near beach and lovely bike rides through the forest on traffic free trails. If you're googling, make sure you get the right Zagarella as there are two 😀 this one is about 8 km from La Tranche in the southern Vendee.
Don't forget to leave a review of the French and other European campsites you have visited!
Le pin was a lovely site and location lots to do with the lake close by as well. It has been improved since we were there. But I may go for a site near the beach if the reviews were good . That would be a bonus not to have to drive all the time .
Camping Les Pirons in Les Sables D'Olonne is a busy site but still quite nice. Close enough to the main town (there are (were anyway) regular buses into town) but in a quiet suburb near the coast.
There are no reviews of the site on here, but if you check tripadvisor there are quite a few.