I've not watched every film where MADAME STARS but off the top of my head some ESSENTIELLES are:
- La Dentelliere (or MADAME playing NICE and FRIGID if you can believe THAT)
- Violette Noziere (elle est ICONIQUE ici)
- La Separation
- Un affaire de femmes (MADAME as an abortionist? je dis oui

)
- Amateur (a must-see if you fancy MADAME playing a PVC-wearing NUN who writes PORNOGRAPHY with a penchant for POWER DRILLS)
- La Ceremonie (un autre great Chabrol and she's PITCH PERFECT)
- La Vie Promise
- Home
- That Korean film where she plays three people (I've forgotten the name)
- 8 Femmes (a bit OBVS, but she really brings it)
- The aforementioned L'Avenir, Copacabana, Valley of Love
She's in lots of other great films as well that are not necessarily STARRING VEHICLES (Loulou, Coup de Torchon, Time of the Wolf, Amour, etc). All the Chabrols with her that I've seen are interesting, and she's done lots of American and French high-trash which are definitely still worth watching like 'Elle', 'The school of flesh' (any excuse for a little RENDEZ-VOUS avec Vincent Olivier), 'The bedroom window' or that one where she fucks her teenage son
She works with first-time directors often and many women directors too so she ends up in the most OFF-BEAT projects, another reason why I love her.