1. The Adventures of Tarzan
Tarzan spurns the love of La, Queen of Opar. When he isn't trying to keep the Bolshevik Rokoff and Clayton from reaching Opar, he is attacked simultaneously by two lions, dropped into a pit when a volcano splits the ground, nearly sacrificed by sun worshipers, and so on.
It has an average vote of 5.8 on TMDB.
2. The Hope Diamond Mystery
The true story of Lord Francis Hope who inherits the Hope Diamond and marries showgirl May Yohe. Lord Francis Hope gambles away the family fortune and May Yohe leaves him. Another suspected curse of owning the Hope Diamond.
3. The Secret Code
A superhero known as The Black Commando battles Nazi agents who use explosive gases and artificial lightning to sabotage the war effort.
It has an average vote of 4.8 on TMDB.
4. The Secret of Treasure Island
A variety of people are searching for a long-hidden treasure somewhere on an island. Chapters: 1. The Isle of Fear, 2. The Ghost Talks, 3. The Phantom Duel, 4. Buried Alive, 5. The Girl Who Vanished, 6. Trapped by the Flood, 7. The Cannon Roars, 8. The Circle of Death, 9. The Pirate's Revenge, 10. The Crash, 11. Dynamite, 12. The Bridge of Doom, 13. The Mad Flight, 14. The Jaws of Destruction, 15. Justice
It has an average vote of 4 on TMDB.
5. G-Men Never Forget
An escaped criminal impersonates a Police Commissioner, causing no end of trouble to a determined Federal Agent.
It has an average vote of 7 on TMDB.
6. The Iron Claw
Only Episode 7, "The Hooded Helper," of this 20-Episode Serial is known to survive. All other episodes are believed to be lost.
7. Dick Tracy Returns
Dick Tracy battles spies and saboteurs in his efforts to bring to justice the Stark gang, a criminal family led by the vicious Pa Stark.
It has an average vote of 5.8 on TMDB.
8. Deadwood Dick
Columbia's 11th serial and the first western serial that James W. Horne solo-directed.
9. Jungle Jim
Two safaris enter the African jungle intent on finding a white girl who is the heiress to a fortune. One safari, led by Jungle Jim, wants to make sure she gets the news that she is now a rich woman. The leaders of the other safari want to kill the girl so they can try to get hold of her inheritance.
It has an average vote of 4.8 on TMDB.
10. The Fighting Devil Dogs
Two marine lieutenants battle a masked would-be world conqueror who uses electricity as a weapon.
It has an average vote of 6 on TMDB.
11. The Phantom
Two expeditions are trying to reach the Lost City of Zoloz -- one headed by Professor Davidson, a scientist who wants to establish an archaeological site, and the other by a greedy treasure hunter who wants to keep the fabled treasures of the city for himself. An agent of a foreign power also wants to establish a secret airbase there, so he stirs up the natives against The Phantom, who has been able to get them to stay peaceful so far. When The Phantom is murdered, his son takes his place and sets out to restore peace to the jungle and stop the agents' and the treasure hunters' nefarious plans.
It has an average vote of 6.222 on TMDB.
12. The Railroad Raiders
A silent movie serial
13. Junior G-Men of the Air
A group of street kids battle a terrorist gang led by a Japanese spy.
It has an average vote of 6 on TMDB.
14. Flash Gordon
Disaster seems imminent when scientists discover that the planet Mongo is about to crash into Earth. Luckily, heroic young Flash Gordon is on hand to lead an investigative mission into outer space and onto the speedily approaching planet. There, he and his best girl, Dale, who is along for the ride, learn that Ming, the devious ruler of Mongo, has purposely put the planet on a collision course with Earth, and only Flash can stop him.
It has an average vote of 6.3 on TMDB.
15. Drums of Fu Manchu
The nefarious Dr. Fu Manchu searches for the keys to the tomb of Genghis Khan, in order to fulfill a prophecy that will enable him to conquer the world. His nemesi, Dr. Nayland Smith and his associates fight to keep the evil doctor from getting his hands on the keys. In 1943 the serial was edited together into a feature movie also called Drums of Fu Manchu.
It has an average vote of 6.1 on TMDB.
16. The Great Secret
A wealthy young athlete comes to the aid of a beautiful heiress, whose fortune is being threatened by two arch villains, The Great Master and Doctor Zulph.
17. The Great Adventures of Captain Kidd
Two British officers are assigned to collect information to convict Captain Kidd of piracy.
It has an average vote of 4 on TMDB.
18. Flying Disc Man from Mars
Mota is a Martian representative, who has come to impose interplanetary law on the Earth ; opposing his authority is Kent Fowler, who resists the alien plot, without understanding its details.
It has an average vote of 4.8 on TMDB.
19. Federal Operator 99
Jerry Blake teams-up with Joyce Kingston to thwart the plans of escaped crime boss Jim Belmont.
It has an average vote of 6 on TMDB.
20. Hawk of the Wilderness
An expedition arrives on an uncharted jungle island to rescue the local natives, led by a jungle boy, from a volcano that is about to erupt.
It has an average vote of 7 on TMDB.