Here are The Traveling Professor's picks for 4 Paris Restaurants:

Bistrot Paul-Bert. 18 rue Paul-Bert, 11th arrondissement.  Métro: Faidherbe-Chaligny.
Travel out to this truly neighborhood bistro experience with its traditional decor and blackboard menu.  It has an extensive wine list for such a small place. Try the entrecôte (rib-eye steak). Prices are in the 20-30 euro range.  Closed Sunday/Monday and in August.  No website.  Telephone:  01 43 72 24 01.

Le Train Bleu. Gare de Lyon, 12th arrondissement.  Métro: Gare de Lyon.  RER A and RER D.
Located in the Gare de Lyon train station in the 12th arrondissement.  The beauty and grandeur of this Belle Époque restaurant compensates for the relatively expensive pedestrian food.  In all fairness, I was with a group of about 20 people and we ordered from a special menu.  At about €20 each, the pricey cocktails may incite another French Revolution.  As I said, the food was unexceptional, but everyone else I know of who has eaten here likes it. Reservations recommended.  No A/C.  Website: www.le-train-bleu.com.

Café Constant. 139, rue St. Dominique, 7th arrondissement.  Métro:  École  Militaire.  
A casual and relatively inexpensive spot near the ET.  Legendary Chef Christian Constant makes French food easy. Where else are you going to get dishes like tartare of oysters, seabass and salmon seasoned with ginger and lemon created by a Michelin-starred chef?  Or how about veal cutlet from the Basque country with white Tarbais beans?   I always have room for the dreamy Île Flotante for dessert. One of my top picks.   About €100 for two.  Website:  www.cafeconstant.com.

Les Cocottes. 135, rue St. Dominique. 7th arrondissement. Métro:  École  Militaire.  
Another Christian Constant gem.  Set up almost like an American diner with a French slant, it is casual and not expensive.  The unique main dishes are served en cocotte, or casserole style.  You are likely to see Chef Constant there, and most likely, he would love to chat with you.  Website: www.maisonconstant.com/les-cocottes.

Travel with The Professor on his small group tours to Paris.