When "Action Comics" debuted in June, 1938, little did anyone suspect it would one day be looked at as perhaps the most important comic book in history. Though he debuted on the cover, Superman was never intended to blaze a trail for thousands of characters after him, but that's exactly what the world's first superhero did.

RELATED: The 25 Most Important "Detective Comics" Issues Ever Published

After rebooting in 2011 with a new #1 issue, "Action Comics" returned to its original numbering in June 2016 when Issue #957 hit the stands. With the return to its original numbering, CBR takes a look back at nearly 80 years worth of DC Comics' highest-numbered title to discern the 25 most important issues of "Action Comics" ever published.

25 "Action Comics" #1



In the debut of its new adventure-oriented anthology, National Comics (now known as DC Comics) published an edited version of a comic strip pitch by young comic creators Jerry Siegel and Joe Shuster. In this strip, the pair introduced the world to one of the most famous fictional characters ever created, intrepid reporter Lois Lane.

We also meet Lois' co-worker at the Daily Star, Clark Kent, who is mild-mannered and clearly not as interesting as Ms. Lane. Of course, he's also, in effect, the world's first comic book superhero, Superman, a character who would change comic books forever, and inspire an entire genre. Not bad for a short strip in an anthology comic book.

24 "Action Comics" #6



One of the oddest aspects of the early days of Superman is that Siegel and Shuster were not paying nearly as much attention to all the background characters as later-day fans were. Heck, Superman had not even appeared on a cover of "Action Comics" since his debut in #1, and Shuster could barely keep up with the strip. As a result, you get situations like this one, where there is an unnamed office boy in this issue. No one calls him Jimmy Olsen, but after the "Adventures of Superman" radio series establishes that Jimmy is a cup reporter at the Daily Planet, this appearance was retroactively determined to be his debut. I personally think his "real" comic book debut is in Superman #13, when he is actually referred to by name, but this issue has become a significant part of the Superman mythos regardless of whether it is the actual Jimmy or not.

23 "Action Comics" #11



When it comes to early Superman appearances, one of the more fascinating things to watch is how Superman's traditional powers slowly but surely develop. In this issue, written by Siegel, penciled likely by Paul Cassidy and inked by Shuster, we see Superman use his "X-Ray eyesight" for the first time.

22 "Action Comics" #23



In this issue, written by Siegel, penciled by Shuster and inked by Paul Cassidy, we hear the name of Lois and Clark's place of employment as the Daily Planet for the first time. That's historic in and of itself, but even more important is the villain who is introduced in this issue: Lex Luthor (although he is not given that name as of yet). Luthor would go on to become Superman's greatest nemesis, and one of the most famous villains in history.

21 "Action Comics" #64



Despite the introduction of Lex Luthor (and the accidental balding that gave him his distinct look), Superman's most common villain in "Action Comics" during the 1940s was the Prankster. I almost gave his first appearance a spotlight, because, seriously, Superman fought him a lot, but then I figured no one cares about the Prankster, so I'll spotlight a similar villain from the same era who people at least know as he carried over into the modern day Superman mythos. The Toyman made his debut in this issue, written by Don Cameron and drawn by Ed Dobrotka and George Roussos.

20 "Action Comics" #65



One of the most mysterious of Superman's superpowers is his ability to fly. By that, we mean it's difficult to pin down which comic book he first flew in. This is because artists would accidentally depict him as flying in various issues. The first definitive example of Superman flying, though, occurred in 1943's "Action Comics" #65, years after Superman had been regularly flying in the Fleischer Studios Superman cartoons and the Famous Studios Superman films that followed. By "definitive," we mean the script says, "fly," Superman says, "Up, up and away!" and the whole nine yards. This is no artistic mistake.

19 "Action Comics" #241



Superman had mentioned a "Secret Citadel" before, as well as a "Fortress of Solitude," but said fortress was more of a castle. It was not until 1958's "Action Comics" #241 (by Jerry Coleman, Wayne Boring and Stan Kaye) that readers actually got to see the classic Fortress of Solitude that is located in the Arctic, complete with the giant key needed to open the door -- something only someone like Superman could do.

18 "Action Comics" #242



The very next issue, we meet Superman's second-greatest villain, the evil Brainiac, in a story by Otto Binder and Al Plastino. It is a good thing the Fortress of Solitude was introduced in the previous issue, because we meet Brainiac after he shrank a number of cities on Earth, placing them inside bottles. As a result, Superman discovers a shrunken city from Krypton on Brainiac's ship, as well!Superman shrinks down and enters the city of Kandor. The city's residents help him save the cities of Earth, but there is not enough power to enlarge Kandor, so Superman takes them to his Fortress, where he keeps them safe. After years of not a whole lot of important events in the pages of "Action Comics," in the late '50s/early '60s the comic finds itself heating up!

17 "Action Comics" #252



Metallo is a villain, so who cares what he thinks? At the same time, you kind of feel bad for him, and he's been a pretty notable Superman villain over the years. However, his debut occurred in "Action Comics" #252, the same issue where Supergirl made her bow in a story by Otto Binder and Al Plastino. Superman's Kryptonian cousin, Kara Zor-El was sent away after her home was threatened by Kryptonite poisoning. Superman decides to place her in an orphanage, having her vow not to reveal her powers to the world, as Superman thinks she would do more good as a "secret weapon" he could hold in reserve for when the need arises.

16 "Action Comics" #254



The "Superboy" and "Superman" comics had a weird relationship back in the day, as ideas would often be tried out in "Superboy" before being brought over to the main "Superman" books. Major parts of the mythos, like red kryptonite and Krypto, both debuted in Superboy before moving over the main title. That was the case with the concept of Bizarro Superman, who first showed up as Bizarro Superboy before making his "adult" debut in this issue by Otto Binder and Al Plastino. (It is kind of crazy how many characters Otto Binder created in his career).

15 "Action Comics" #285



After a few years as Superman's secret weapon, Supergirl made her well-earned public debut in this issue, written by Jerry Siegel (who had recently returned to writing Superman comics at the time) and drawn by Jim Mooney. The lead story, where Superman introduces the world to Supergirl, dovetails into Supergirl's first solo adventure in the public eye. She even gets to meet President Kennedy!

14 "Action Comics" #300



Science fiction legend Edmund Hamilton wrote this classic story, "Superman Under the Red Sun!" where Superman travels to the future where the Earth is now surrounded by a red sun. Stripped of his powers, can Superman find a way home? He's forced to push himself in ways he's never pushed himself before in this classic tale, which was so important, it was included in the very first "Best of DC" digest in 1979.

13 "Action Comics" #340



Jim Shooter was still a teenager when he was given the chance to write a fill-in Superman story in the pages of "Action Comics." He did not take that opportunity for granted, introducing a classic Superman villain. The Parasite is one of the very few Superman villains who can go toe-to-toe with Superman due to his ability to siphon Superman's powers. He's also the first villain Superman actually used his heat vision on! The issue was drawn by Al Plastino.

12 "Action Comics" #484



DC celebrated the 40th anniversary of "Action Comics" #1 with this charming story by Cary Bates, Curt Swan and Joe Giellam, where the Earth-2 Superman has his identity as Superman erased. Now fully devoted to his career as Clark Kent, the new crusading Clark gains the interest of Lois Lane. The two begin to date and ultimately marry. His Superman identity is eventually revealed to him, but even after regaining his memory, the two remain married. It's all wrapped in a gorgeous Jose Luis Garcia-Lopez cover.

11 "Action Comics" #521



Vixen is a neat character and she will soon be appearing as a regular on the TV series "Legends of Tomorrow," but it is more of a statement on how "Action Comics" (which remained an anthology for many years) did not get as many notable stories as its sister title, "Superman," did. Thus, one of the 25 most important issues of "Action Comics" is the debut of the cult-favorite character, by Gerry Conway, Curt Swan and Frank Chiaramonte.

10 "Action Comics" #544



To celebrate the 45th anniversary of "Action Comics," DC revamped Superman's two biggest villains, Lex Luthor and Brainiac. Luthor got a much upgraded armor in a story by Cary Bates, Curt Swan and Murphy Anderson, while Brainiac was completely transformed into a living computer by Marv Wolfman and Gil Kane. These versions of the characters came at just the right time, as toy maker Kenner's Super Powers line of action figures would debut soon after. These are the versions of the classic villains that appeared in the toy line, making them stick in the hearts and minds of kids of that era.

9 "Action Comics" #583



In the final part of Alan Moore's classic "imaginary story," "Whatever Happened to the Man of Tomorrow?" we discover which of Superman's villains has been manipulating a terrible turn of events in Superman's life. In the end, Moore and artists Curt Swan and Kurt Schaffenberger (two of the all-time greatest Superman artists) put a wonderful bow on the concept of the Silver-Age Superman Family.

8 "Action Comics" #584



Following the character-rebooting "Man of Steel" miniseries, this issue was the first official Post-Crisis issue of "Action Comics," as writer/artist John Byrne and inker Dick Giordano turned "Action Comics" into a team-up series for a while. Byrne also wrote and drew the relaunched "Superman" solo series, while Marv Wolfman and Jerry Ordway took over the re-named "Adventures of Superman."

7 "Action Comics" #600



"Action Comics'" relatively brief stint as a team-up title came to a close with the epic 600th issue, where John Byrne and George Perez addressed the idea of what would happen if Superman and Wonder Woman got together? They also have a massive fight against Darkseid in this issue. This also marked the end of "Action Comics" as a monthly title. "Why would that be," you ask? Well...

6 "Action Comic Weekly" #601



in 1988, DC Comics made the bold move, turning "Action Comics" into a weekly anthology series. Each issue contained a two-page Superman story, and a recurring Green Lantern feature, but everything else was up for grabs, with characters like Demon, Nightwing, Black Canary and the Blackhawks rotating in and out of the book. An amusing side effect of this weekly stint is that "Action Comics" was able to leap ahead of "Detective Comics" in numbering; "Detective" launched first, but "Action Comics" is now higher in issue number. The weekly experiment didn't even last a year before DC returned the book to a monthly, Superman-based title.