In reply to 12SHughes:
We've done trips to Laruns / Vallee d'Ossau and Cauterets, plus a chunk of the HRP through Northern Catalonia and Andorra. They were all fairly great.
I can't recommend specific campsites but one thing that I would recommend is planning to spend nights out in the hills, either camping or in unmanned or manned refuges. Unless you're super-fit, there's a bit of a tendancy on a day walk to find that you're just getting to the good stuff when you have to turn around and come back.