8. ACTION COMICS #242 (1958)

The villainous Brainiac made his debut in this issue, complete with a plan for world domination and a pink and black unitard. Even though his outfit may leave disturbingly little to the imagination, Brainiac has gone on to become one of the most feared villains in the DC Universe and this cover gave readers their first glimpse at the emerald menace.

While pretty understated by today’s standards, this cover represents all that is good about the Silver Age of comics. Everything from the bright colors to naïve dialogue makes this cover the perfect time capsule for a simpler time in comics.