Hi,
My favorite restaurant there is La Vache et le Cuisiner which is at 16 Rue de Trois Freres (Three Brothers Street). Take the subway to Abessess, turn left out of the station onto Rue de Yvonne du Tac (it's something like 180 steps up to the street so you may want to take the elevator), walk 2-3 blocks down Yvonne du Tac until you come to Le Progres on your right. Then turn left on Rue de Trois Freres. It's up on your right. It's run by Monsieur Didier and Kathleen: great traditional French food, good service, good prices and great atmosphere.
I've never had a bad meal there. Sometimes I'll just tell them to bring me whatever the specials are. Really, really delicious soups, which may go well at Xmas time.
Good luck