The X-Men #80

The cover of this 1973 Marvel issue says it all — the Juggernaut looms enormous in the foreground, towering over a scrambling team of X-Men (Cyclops, Iceman, Beast, Marvel Girl, and Angel visible in the background) as he declares it's his turn to strike back. Gil Kane's pencils and Frank Giacoia's inks give the villain an almost overwhelming physical presence, making the X-Men look genuinely outmatched against their unstoppable foe. With a story by Roy Thomas and interior art by Werner Roth and John Tartaglione, this is a satisfying slice of early-'70s Marvel mutant action.