The restaurant Au Moulin Vert (http://www.aumoulinvert.com/) was actually on and named after the street where we lived, Rue de Moulin Vert, which means street of the Green Windmill. It was constructed on the former site of an actual Windmill and was frequented by novelists such as Victor Hugo and George Sand. We ate on the glass covered porch area that has the feel of a greenhouse.
The Art Deco style restaurant called Zeyer Brasserie (http://www.lezeyer.com/) has been open since 1913. We passed by this restaurant every day as we walked home from the Metro, and were taken by the gorgeous Deco ceiling. When we finally dined there, the food was just OK, but I did have one of my favourite appetizers (or in French, they called it "Entrées" which confused me at first). It was a dish of pan fried prawns coated with fried angel hair pasta and covered with pesto sauce.
Le Coupole (http://www.lacoupoleparis.com/en/) is another restaurant in the Montparnesse area with stunning decor. The pillars were painted by students of Matisse and Fernand Léger, and you can see their influence in the results. The bright blue ceiling seemed more in the style of Surrealism than Impressionism with images of alien looking creatures and the semi nude redhead covered by what looked like bubbles and octopus tentacles . Even the food seemed like art, as shown by my lobster salad.