The Defenders #10

The cover of this 1973 Marvel gem says it all — the Hulk has Thor in a crushing bear hug, Mjolnir still in the thunder god's grip as the two titans strain against each other in a rubble-strewn cityscape. Surrounding medallions on the left identify the rest of the Defenders roster — Doctor Strange, Namor, Valkyrie, Silver Surfer, and Hawkeye — hinting at the larger Avengers/Defenders War raging around this climactic showdown. John Romita's cover art crackles with raw physical tension, perfectly selling the chapter's title "Breakthrough!" as one of the Bronze Age's most thrilling hero-vs-hero matchups.