I've been to Parc Asterix. I think it is the nicest park I've ever been too; the theming is excellent and pretty funny as well. I went on a semi-crowded day, but I still had a great time. Tonnerre de Zeus is one of the best woodies around. I would recommend it to anyone in the France area, it is definitely worth a day's visit.
-------------
http://www.bolliger-mabillard.com