Diana Wynyard is wonderful (IMO) in "Cavalcade". Her Bella in "Gaslight", for me, is very watchable, but she doesn't quite measure up to Ingrid Bergman's performance. I think the reason is that Wynyard approaches the character as a shy, mousy type given to overdramatic hysterics. Bergman could never be mistaken for shy or mousy in "Gaslight", but she takes a demure approach and her breakdowns are more psychologically complex.