Ok. I get it. Batman has a utility belt. He's always got the right tool for the job, just like a Wizard. But any further than that, the metaphor breaks down. Batman is obviously mundane. He punches things with his fists and throws bat-shaped shurikens. He is one of the few superheros that explicitly wears armor and has a belt full of technological items. I know what you're thinking. "But Stan," you say, "Magic is a metaphor for technology and Batman always has the right technological solution." And you'd be right. But Batman is a master detective who sneaks, climbs, jumps, tumbles, mixes it up in melee, and uses technology a la Use Magic Device. Technology that he doesn't make himself. Batman is some kind of Rogue/Monk/Ninja thing. His strengths are in his skills. And the Monk/Ninja thing makes sense with his background, having trained in East Asia under R'as al Ghul and his Ninja assassins. "What about armor?" you ask, and I tell you that a monk or ninja is still the same with armor, they just don't get the AC bonuses or speed buffs. And there are ACFs and Archetypes that allow monks and ninjas to wear armor. Far easier than taking armor proficiency and Arcane Armor Training on top of Improved Unarmed and every combat maneuver feat that Batman obviously has.
So What Superhero best represents a Wizard?
Well, my first thought would be Superman because he's absurdly powerful, as are Wizards. But you know who else is absurdly powerful? Sorcerers. And Sorcerers only have a few Superpowers, just like Superman, whose powers are inborn and unchangeable. Lots of power, limited versatility. His one weakness? Kryptonite, aka DC's Antimagic Field. Superman is also not super smart, and thus not intelligence-based. Lots of bad guys manage to trick Superman quite easily, because fighting him is impossible, but tricking him isn't any harder that tricking a normal guy.
If we cross the DC/Marvel divide we come across another hero who might be an accurate representation of a Wizard. The Hulk. Nah, just kidding, he's a straight Barbarian. I'm talking about Iron Man. Yes, Tony Stark is mundane. But we've already established that magic is a simple metaphor for technology, and Tony Stark has a ton of tech at his fingertips. And he's a genius (aka high intelligence) who, unlike Batman, makes his own tech. "But wizards don't wear armor!" you say. Except the Iron Man suit isn't really a suit of armor. It's a mobile weapons platform with its own capabilities, far exceeding a mundane suit of armor. It has scanners and its own intelligence and several different types of weapons as well as physical strength and imperviousness and flight capabilities. In our metaphor, it's spell armor. It takes Tony a couple rounds to get the armor on, like it takes a Wizard a few rounds to buff himself into a God. It's Tony's spellbook. Tony without his Iron Man suit is basically the same as a Wizard with no spellbook: a really smart mundane guy. The Iron Man suit is also subject to EMPs, lightning strikes, and other forms of Marvel Antimagic, but Sorcerer Superman never has to worry about not having his superpowers because they're in the other room. There is one last, defining thing that makes Iron Man the true representation of a Wizard. Superman is stuck with what powers he already has because they're inborn. Batman is limited to what he can accomplish with his body and whatever items he has available. Iron Man, however, is constantly tweaking and redesigning his suit, giving it new capabilities. When his suit can't handle something he goes home and fixes it until it can, much like learning and preparing new spells.
Superman is, by default, the strongest and most OP superhero. Batman is my favorite for a number of reasons. But Iron Man is the closest approximation to a D&D Wizard.