There are several great works of French literature, but I will try to narrow it down to just a few. One title that you may not be expecting is Beauty and the Beast by Madame de Villeneuve, written in 1740. This is the piece of literature which the fairy tale is based on, but this story is actually pretty different.
In this same vein, The Tales of Mother Goose by Charles Perrault, written in 1696 is one of the most commonly read collection of stories still today. Dangerous Liaisons by Pierre Choderlos de Laclos, written in 1782 was a piece of literature which was very popular in France during the 18th century.