The Amazing Spider-Man #21

Steve Ditko's cover for this 1965 Marvel issue captures a thrilling three-way clash — Spider-Man swings upside-down at the center while the flame-wreathed Human Torch blazes in from the left and the green-clawed Beetle looms menacingly from the right. The banner proudly announces this as a co-featuring team-up (or showdown?) involving both the Torch and the Beetle, making the 12-cent price tag feel like a genuine bargain for the era. Stan Lee and Ditko were clearly swinging for the fences with "Where Flies the Beetle...!", packing one cover with enough energy and attitude to back up the bold claim that this is the Marvel Age of Comics.