Beam Me Up, Scotty!: The phrase, "Able to leap tall buildings at a single bound," was often misremembered as, "Able to leap tall buildings in a single bound." Notably, when the phrase was used in an episode of Wheel of Fortune, two of the contestants tried to guess the phrase while the letters "A", "I", "N", and "T" had not been uncovered, while the third declined to guess. Neither of the two guesses were right.
Missing Episode: One of the most infamous in Radio history. All stories broadcast from August 31, 1942 to September 3, 1945 are either wholly or partially missing, leaving several hundred episodes simply gone. This includes the very first appearance of Kryptonite in all fiction, as well as the first appearance of Batman and Robin and supporting character Candy Meyers.
Recycled Script: Several stories are lifted almost word for word from the early years of the run, while others are repeats with the idea that the characters are having flashbacks to the whole adventure, even the parts they weren't there for!
Reality Subtext: Stories would occasionally completely shift focus to Batman and Robin in order to give Collyer a little time off.
Science Marches On: From the belief that space is hot to the idea that the far side of the moon has oxygen and could support life, anything involving outer space is subject to this.
The Other Darrin: The radio series was ripe with this, having run for over a decade.
Lois Lane was played by three different actresses throughout the run. Originally played by Rolly Bester, she was swiftly replaced by Helen Choate. After only two months, Joan Alexander, who had been cast early on, took over the role for most of the series.
Bud Collyer played the titular Superman from 1940-1950, save for a brief stint in World War II when he was called into service and needed to be replaced. In 1950, he quit and Superman was recast by Michael Fitzmaurice for the brief remainder of the run.
Jackie Kelk played Jimmy Olsen for seven years, finally leaving the show in 1947. Jimmy's new actor was Jack Grimes.
Trivia for the television show:
…But I Play One on TV: George Reeves had it much rougher than Christopher Reeve, as his younger fans would often try to test his invulnerability. The worst case was when a boy brought his father's gun to a set to see if Superman was really bulletproof. Reeves convinced him to hand over the gun saying that the bullet would bounce off and hurt somebody else. (The incident was depicted in the biopic Hollywoodland). When he appeared on I Love Lucy, Reeves was only referred to as "Superman" to not break the illusion for younger viewers, enforcing this trope.
Celebrity Voice Actor: Somewhat; in the Latin American Spanish dub, Jimmy Olsen was one of the first roles done by the late Puerto Rican astrologist and actor Walter Mercado, as he was previously a voice actor before in his native Puerto Rico, before the voice acting industry of his country dissapeared in the 1960s, forcing him to move to other artistic careers.
Enforced Method Acting: In "Night of Terror", the actor playing the thug who knocks out Lois accidentally hit Phyllis Coates hard enough to render her unconscious.
George Reeves was trying desperately to avoid this trope, but sadly even his death cemented it. Some documentaries dispute that while Reeves had gotten tired of playing Superman, he had come to accept that the role would be what he would be best known for and embraced it. Tragically, this acceptance was apparently shortly before his death.
To a lesser degree, Jack Larson tried to avoid being known too much as Jimmy Olsen, but it didn't work.
The Other Darrin: Noel Neill replaced Phyllis Coates as Lois Lane in the second season. In an interesting twist, Noel Neill was also the first actress to play Lois Lane on live action film, having first played the intrepid reporter in the 1948 and 1950 Superman serials (films divided into episodic shorts that used to be played in movie theaters before the main feature).
