Ok, here's an idea for a fun contest. I post a section from a comic cover and you guys try and guess what cover it's from.Whoever guesses correctly, gets to post a portion of a cover themselves, and we all get to guess. It's not good form to post a very tiny part of the cover, as it makes the contest too difficult.
Here's my starter - a clue is that this particular cover (like all of mine) is from the Silver-Age.
Art by Howard Purcell and Dan Adkins, except for the Black Knight. The GCD says he was drawn by John Romita. The critter over the Knight's left hand reminds me of Dzamor from the "Enchantress" series, which Purcell also drew.
According to Nick Caputo the script, by Steve Skeates, was a repurposed Spectre script.
There's no trick to the theme. What these issues obviously have in common is it.