Rare collectible comic book issues include issue one of "Action Comics," issue 27 of "Detective Comics," issue one of "Batman," issue 40 of "Adventure Comics," and issue three of "All Star Comics," according to SellMyComicBooks.com. Each issue marks a major event in its comic book series.
Issue one of "Action Comics," published in June of 1938, introduces the Superman character. The cover shows an iconic image of Superman lifting a green car over his head. A copy in near-mint condition can sell for over $2 million.
Issue 27 of "Detective Comics," published in May of 1939, marks the first appearance of Batman. This issue is worth a minimum of $25,000 in poor condition. In the spring of 1940, Batman began to appear in his own self-titled comic book, "Batman." Issue one of "Batman" introduces two major characters in the series – the Joker and Catwoman, who is first referred to as "The Cat."
Some collectors consider issue 40 of "Adventure Comics" the rarest key issue in the series. In this issue, the writers began to incorporate superheroes. The Sandman is the first superhero to appear in the series, though he had appeared in other comic books before. In issue 40 of "Adventure Comics," he stars in the story "The Tarantula Strikes."
Issue three of "All Star Comics" marks the first appearance of the Justice Society of America. The group brought together the Flash, Hawkman, Green Lantern, Dr. Fate, Hourman, Sandman, the Spectre and the Atom.