One of the neat things about the Hulk is that he forces superheroes to solve problems without their usual go-to solution of a punching contest, because if you get into one with the Hulk, you're generally going to lose. He's beaten up gods and entire teams of superheroes and made it look easy. The Hulk is the strongest one there is. It's even one of his catchphrases. Another is "the madder Hulk gets, the stronger Hulk gets." So, sure, godlike beings like Thor and Hercules might have an edge on the Hulk at first, their daring to resist him usually just makes him mad enough to kick their greasy Eurotrash faces in. Underdogs like Iron Man or the Thing might score the occasional upset, but it's usually due to extenuating circumstances. (Even Veronica in Age of Ultron probably couldn't have taken out the Hulk if he weren't finally distracted by all those terrified people... but let's stick to the comics; movies are always a bit more bound by real-world physics.) Still, there have been a few heroes who have consistently demonstrated the power levels to lay the Hulk flat on his ass. And to be clear, we're talking about the big green Hulk, not the somewhat weaker and shrewder, gray-skinned "Mr. Fixit" Hulk or even the jacked-up version of the character from World War Hulk. Nor do we mean opponents who could use non-punching super-powers to take Hulk down, like Professor X or the Flash. Even Namor's victories over Hulk are kind of a cheat, as they involve as much drowning as hand-to-hand combat. These are only heroes who could outpunch the big guy at the top of his game, when he's full of gamma and gumption and ready to roar. There aren't many more than this!
T Campbell has written quite a few online comics series and selected work for Marvel, Archie and Tokyopop. His longest-running works are Fans, Penny and Aggie-- and his current project with co-writer Phil Kahn, Guilded Age.