The Avengers #168

George Pérez and Terry Austin deliver a wonderfully kinetic cover for this 1978 issue, showing Iron Man, the Scarlet Witch, the Beast, Wonder Man, Thor, and Vision surging into action — while a massive, ominous purple-and-yellow figure looms in the foreground, apparently having breached Avengers Headquarters with alarming ease. The cover copy teases "the most unexpected confrontation ever," with the Guardians of the Galaxy guest-starring alongside Starhawk's desperate duel promised inside under the title "First Blood." It's a jam-packed, pulse-quickening issue that showcases exactly why Earth's Mightiest Heroes were firing on all cylinders in the late Bronze Age.