[Gene Colan & Neal Adams]
One of my all-time favorite comic books is Marvel Super-Heroes. It had been known as the venerable Fantasy Masterpieces and housed both Silver Age and Golden Age reprints, but changed its title to more properly reflect its role as Marvel's "Showcase" comic for a brief time. (Note: With lots of reprints still too.)
[Howard Purcell & Ron Frenz]
Lots of great comic book ideas were debuted in its pages and a lot of heroes were given their first try-outs as solo acts too.
[Gene Colan & Jim Valentino]
And these covers proved to be quite memorable as many have been used as inspiration for great "swipes" or more the more genteel "homages" over the intervening decades.
Great covers deserve great swipes.