L'Ardechois at Vallon was one of our favourite sites, and is walking/cycling distance to Vallon Pont d'Arc - and although a busy site, is lovely, with a great pool, river access, and a nice bar and restaurant and immaculate sanitary blocks. Vallon is a busy place, but we love it there, and there are a great number of reasonably priced restaurants. Les Ranchisses at Largentiere is also well situated, though not a site on the Ardeche itself, but with good pools and restaurant - one of the best campsite restaurant meals we've had. Largentiere is a pleasant mediaeval village, with some interesting narrow streets, and a great market.
We stayed some years ago at Ardeche Camping at Privas - again walking distance into the town, and nicely situated, with a developing pool complex - but though that was a lovely site too. Again some good value restaurants and bars. Both the latter take Camping Cheques towards the end of August.
We use either Camping Cheques, or an ACSI card these days - which are accepted on a wide range of sites, (see
www.campingcheque.co.uk and
www.campingcard.co.uk) for details. Between the two they offer a variety of sites in the Ardeche, both the southern part, or the north (we've driven though/around/visited - but not stayed on a site there).
We tend to go for sites with 'full facilities' - in that we like a pool and bar, but have never found any of the sites described as 'too commercialised' (but I'm talking about lower season, towards the back end of August and not mid-July to mid-August when sites can be very different!).
If you fancy any of the above sites, I'd be happy to come back with more details.
Whilst in the area, some must sees are: Gorges of the Ardeche - though go early morning. Aigueze at the bottom end is delightful for coffee or lunch, and a walk along the cliffs to take in the views of the river. La Beaume is worth a half day or longer, for a swim in the river, a coffee sitting under the plane trees, watching locals play Boules, higher up the Beaume river for some fantastic river pools and waterfalls for 'wild swimming', the Pont d'Arc - either beach to the north of the south, for watching the canoeing and some nice swimming, Balazuc for some touristy shops, but a lovely riverside beach, Vogue (similar), Ruoms for wonderful ice creams and a Friday market, Vallon for the Thursday market and a coffee in the square people watching, Aubenas for some great shops, and wonderful view over the valley, the Rocher de Sampzon for the cafe at the top, and great views, Lac d'Issarles for a very strange circular blue volcanic lake, the Ray Pic waterfalls (if they're now reopened to the public), Largentiere on market day, Chassiers (if the Fete d'Orgues is on - a fantastic day of small organs, and street theatre), and much much more! If you're fit and able, then do one of the canoe descents - even the mini-descent will take you through some lovely scenery.