In my opinion, one of the more underrated actors of his era, in my opinion... at least in the sense of, you don't realize just how many great films he was in or how he could play a leading part (DOA) as well as a character actor (Liberty Valance, The Killers to an extent, The Wild Bunch).
Not really his best, but I have a soft spot for The Web in which he is named Robert Regan and falls in love with Ellla Rains!