Fonda does a pretty memorable job of playing the sociopathic killer, Frank, in Once Upon a Time in the West. While working as a hired gun for the railroad, Frank leaves a path of death and destruction across the continent. He adds the gunning down of the McBain family to the long list of people who "got in the way" of his plans. He heartlessly stares the youngest McBain boy in the eye, as he kills him with a complete lack of emotion. He forces Jill McBain (Claudia Cardinelli) to be his sex slave, with threats he might kill her if she doesn't "perform well enough". Frank craves power that even his railroad boss can't control, whom he degrades and intimidates at every opportunity. Frank's sociopathic lack of guilt, fear, or any other emotion, as he uses others and discards them, makes him stand out for me as the most memorable bad guy.