Don't miss Parc Asterix (esp if there are youngsters in your party), it is fun on many levels. http://www.parcasterix.fr/monde-la-gaule
As you can see from the French-only web site, this is the "National" theme park. It's clever, quirky and even has a "Foret des Druides" (fun photo op!).
Book online (cheaper), get there early, and plan to have lunch between 12:30 and 13:40 (not a minute later, or all the good stuff will be gone and the Chef away home!). The bookshop naturally has all the themed Asterix stuff you could wish for, as well as some material on the back-story of the books (Gauls, Druids & Romans, Fr history etc.).
Getafix, naturally, is to be found all over the place: http://en.wikipedia.org/wiki/Recurring_ ... in_Asterix