Newbie here. And I've obviously come to right place if people list Fredric March and William Powell among their favorites. I knew Powell's widow, Mousie, for several years before she died. She always referred to him as, "My Bill." I was so envious.
To those two gents I would have to add Jimmy Stewart, and the obvious choices of Tyrone Power, Clark Gable and Errol Flynn. But above all, in my mind, there is, and will always be, William Holden. That smile alone... sigh