I don't love either restaurant but definitely prefer Chefs de France. The food is acceptable, albeit boring and unmemorable, and the atmosphere is lovely. With a little imagination, and a lot of wine, you'll almost feel like you're at a real Parisian street cafe.
Nine Dragons, meanwhile, may be my least favorite restaurant on Disney property. It's mediocre Chinese food for triple the price of the takeout joint on nearly every corner in every major American city. If a restaurant plans to charge that much, it should at least offer authentic Chinese cuisine, not the same Chinese-American junk we all eat at home. Sesame chicken tastes a lot better when you're paying $5 rather than $15.