The GONE WITH THE WIND of French CInema
I feel the only people who know about this movie are diehard fans of the novel, like myself, who've seen almost every film version. It's a shame because not only do I agree with the common opinion that this is the best adaptation, but it's just a really good movie in general.
What's really fascinating to consider is that this was made a full five years before GONE WITH THE WIND. Before Hollywood made arguably the most epic American film ever of the time, French cinema had already done that with this masterpiece.