Action Comics, published on April 18, 1938 (cover-dated June),
by National Allied Publications, a corporate predecessor of DC
Comics, is considered to be the first true superhero comic; and
though today Action Comics is a monthly devoted to Superman,
it began, like many early comics, as an anthology.

As of 2011, this is the only comic to have sold for more than $2
million for a single original copy. It is considered to be the most
valuable comic book of all time.

Superman creators Jerry Siegel (left) and Joe Shuster