There aren't many Golden Age Hollywood stars left, and the death of Jennifer Jones means that there are even fewer.
This is not a new sentiment at all, but I never felt that she was completely suited to the type of movies that Selznick preferred her to do. Not that he handled her career badly, since most of her films are pretty good, but he usually seemed to want actresses to take the heaviest, soapiest roles they could find. This wasn't the most desirable situation even for Ingrid Bergman, who was great at that kind of thing (but whom I would have liked to see more often in comedy). Jones could be good in a soapy film if the director and script were right, as in Madame Bovary (Minnelli) or Love Letters and Portrait of Jennie (Dieterle). But she was more relaxed and fun and appealing in comedy. Even her particular type of good looks seemed more suited to girl-next-door parts than exotic-type women. Not that she looked like the girl next door, just that she was great as a girl next door with a hint of exoticism or passion (or in Cluny Brown, "dirty" urges) in her wholesome style.
She's very funny in Beat the Devil and in Lubitsch's Cluny Brown, despite an off-again, on again British accent that rivals Kevin Costner's Robin Hood. Even Madame Bovary, while obviously not a comic part, is not a saintly Bernadette-type character either. I wish she had done a few other films like that.