If you want to book a special dinner, I recommend this place:
La Grande Cascade | Restaurant gastronomique étoilé au cœur du Bois de Boulogne à Paris
Its in the Bois de Boulogne, which will be a decent taxi ride from the city center, but its a pretty spectacular spot, and a wonderful fine dining experience. It was recommended to me by a long time colleague who was born/raised in France.