You can get decent French food at the Hotel Les Roniers, located about 7km from the center past the American embassy on Rue Tondibia. Heavy on the meat, not too many vegetables, but there are a few decent salads on the menu.
A large pleasant open air restaurant. A seen and be seen place for locals. One time there, we met Alpha-Di, the local designer made big in Paris, along with several models in town for the annual FIMA fashion show.
Favorite Dish: Chicken in peanut sauce, prawns and lobster (don't think about how they got here, a 1000km from the sea!), along with side dishes not often seen in Niger, coucous d'igname, plantains, etc. Swamp rat is also on the menu.