For a while there he seemed interchangeable with James Garner or Rod Taylor (all "amiable 60s leading men" as the reference books would say). Somehow I never wanted to see his Oscar-winning turn in CHARLEY but he was terrific in THREE DAYS OF THE CONDOR, and of course he stars opposite Lana in one of the great guilty pleasures: LOVE HAS MANY FACES! I saw one of his lesser 70s movies last week: OUT OF SEASON made in England where he is the guy between Vanessa Redgrave and Susan George! Looking at his credits it is a long career to which most of today's young actors can only aspire.
William Holden is generally considered too old for his role of the drifter in PICNIC but the pal he visits, Robertson, was also in his 30s then - also playing a character meant to be at least 10 years younger than he was. He was married to the lovely Dina Merrill.