We have already booked a Villa for the Languedoc for next year. We have been there in past years.
Most of the beaches are pretty nice and as you are not going in the main season then you should find the roads quieter than we did as we had problems getting into several coastal towns and when you did finally get in there was nowhere to park!
The Solar Furnace at Odiello in the Pyrenees is worth a visit if you are of a scientific bent.
http://en.wikipedia.org/wiki/Solar_furnace
Carcassone is a good day's visit, when we went there was jousting taking place.
The Canal du Midi is very pretty athough boat trips are quite expensive.
Just down the coast almost on the Spanish border the village of Collioure is very picturesque.
I would be interested for your recommendations when you return.