In 1959, Roberts guest-starred in episodes of "General Electric Theater", "Cimarron City", "Sugarfoot", "Lawman", "", "Bronco", "77 Sunset Strip", "The Detectives", and "House Call". Also in 1959, he co-starred in the film "Ride Lonesome". "If Roberts felt typecast by Westerns, they also provided his finest role in this film, arguably the greatest of the B-movies starring Randolph Scott and directed by Budd Boetticher. Roberts recognized the film's classic structure; his engaging outlaw, Sam Boone, counterpoints Scott's granite-faced Ben Brigade, maintaining the tension of whether they will work together or clash. He similarly played off James Coburn, who was making his film debut as Boone's quiet sidekick, Whit." The same year, he was cast in "Bonanza".