We've recently returned from our first caravan trip to South West France and Green Spain. The difference between the French sites and the Spanish ones were really noticeable - French, pitches very generous and well-spaced out, Spanish - the 3 we saw were almost like a car park, very close together.
In France, we stayed at Camping La Cote http://www.campinglacote.com/gb.html . Very quiet and relaxing. While we were there, an English couple came to stay for a couple of nights and stayed 6 weeks!
We then went on to http://www.campingitxaspe.com/ accross the border in Spain. Small pitches and most were taken up by locals who left their caravans there - they looked like they hadn't moved for years. Quiet, but only stayed a coupe of nights then moved on to our main destination near the Picos de Europa:
Camping la Paz, near Llanes http://www.campinglapaz.com/.
This was an excellent site. You have to let the owner tow your caravan up a very steep drive, so make sure you go first to select a pitch, or he will allocate one which you may not want. Again, pitches were small, but as we were there end June, it wasn't anywhere near full, so we had enough space. Its terraced, very clean with views over the Bay of Biscay.
We also went to look at a site we had originally planned to stay at a few miles away at San Vicente de la Barquerra. So glad we changed our minds as it was just like a caravan dislay with 'vans almost on top of each other.
Weather let us down as that area stayed in cloud so we didn't get into the Picos, but would certainly go again to Camping la Paz.
Sorry I have rambled on, but hope it helps.
Regards
Ken