The super-soldier serum turned scrawny Steve Rogers into the peak of human physical perfection, and his vibranium shield can absorb a direct hit from Thor's hammer without a scratch. Cap is the best hand-to-hand combatant in the Avengers, a master tactician who once outmaneuvered Thanos, and possesses a moral compass so unshakeable he wielded Mjolnir. He doesn't win because he's the strongest—he wins because he does not quit.

The angrier he gets, the stronger he gets—and Bruce Banner's gamma-irradiated alter ego has gotten angry enough to crack continents and punch through dimensions. The Hulk's strength has literally no known upper limit, he regenerates from virtually any wound, and his thunderclap can level city blocks. The only thing scarier than fighting the Hulk is the realization that he hasn't even started trying yet.