French literature is a vast subject. As Stewart said right at the start, we know a bit about the language and literature because they are right next door, if you're British, but I too feel I've only scratched the surface.
We did one book by Gide at school 40 years ago (probably because some of the French teachers were closet gays) and Gide does write a beautifully poetic kind of prose. And we read Camus. But I must admit that I have read very little else written in French.
I did buy a book recently with the no-nonsense title
La littérature française au présent by Domique Viart and Bruno Vercier
, but have only read a fraction of it. What is interesting about this book is that it groups books thematically, e.g. novels about the self, novels about places and landscapes, crime novels, poetry, etc. Also that it gives extended excerpts. And they are all books published during the past couple of decades.
But I feel very ignorant of all the classic French authors, such as the playwrights of yore, such as Molière, Racine, Corneille, the great novelists Hugo, Dumas, Balzac, and a whole plethora of 20th century novelists including Green, Mauriac, Maurois, Sartre, plus the playwrights like Ionesco. Plus the poets.
Libraries with French literature, in translation or the original, are such a boon, because you can borrow and browse until you find an author on your wavelength. Bookshops just encourage you to spend. And you're saddled with the book, even if you don't like it.