What I like most about this film, and Manon des sources, is that while it has merit as a film, for scenery, for acting, etc. it also has an extremely unique, interesting and devastating plot. Because of this, I think it's enjoyable without a need for analytical thought, and is also accessible to all.
It's difficult to rate this on its own because it's the whole ("Florette" + "Manon") that makes this great. Soubeyran's twisted jealousy and hatred is palpable. Ugolin is a fool caught in the ugliness, cruelly but justly made to pay for his sins in the latter film. The story structure is essential and simple like a fable; the lessons are deep and true.