Batman is an absolute fan-favorite both in the comics and in the fandom. Many DC heroes and DC fans love and respect him for his commitment to justice. Besides, some villains find themselves drawn to him for his attitude. Considering that he's an upstanding superhero, it's safe to say that if he was in the Marvel universe, this would remain true.
Whether it is because his bat-themed concept is unique, because he's devoted to crime-fighting, or because he would be among the most prolific Marvel superheroes ever, many Marvel superheroes would flock to him. If Batman was part of the Marvel comics, heroes like Rocket Raccoon, Daredevil, and Ms. Marvel would love him.
10 Rocket Raccoon
One of the strongest members of the Guardians of the Galaxy, Rocket Raccoon went from a criminal to an incredibly committed superhero. Considering that Batman fights for justice just as hard as Rocket and he has a super cool suit, the Guardian would love him immediately.
Batman has a strict no-gun policy, which means Rocket would be disappointed when ransacking through the Cape Crusader's gadgets. However, he would soon discover they are very similar. Like Rocket Raccoon, Batman is an expert tactician and a resourceful hero. Rocket would enjoy a conversation with Bruce any day.
9 Moon Knight
Also known as the Fist of Khonshu, Moon Knight is a mercenary turned vigilante who helps the Moon god enact justice on those who deserve it. He uses the powers bestowed on him by Khonshu, such as enhanced physiology and nigh-immortality, as well as his martial art and weapon expertise to fight crime
Contrary to Batman, Moon Knight has superpowers. However, they're very similar in attitude. They're both nocturnal, melancholic, quiet vigilantes who fight their demons without asking for help. Moon Knight would like Batman because—like him—he sticks to his business until it's time to fight crime.
8 Black Widow
Natalia Romanova, aka the Black Widow, is one of the strongest Marvel heroes who doesn't have flashy superpowers. She was biochemically enhanced in the Red Room, but she can't transform into a gamma being or control the weather. Instead, she relies on her fighting expertise and her previous training as well as her gadgets, just like Batman.
This, combined with the fact that Natalia can relate to Bruce's traumatic backstory, means she could become his biggest admirer. Bruce would surely admire her just as much once he gets to fight side by side with her.
7 Nick Fury Jr.
Both in the MCU and in the comics, Nick Fury is one of S.H.I.E.L.D.'s most important agents. He's completely committed to protecting the Earth, so he has worked hard to ensure it has many guardians. For example, by creating the Avengers Initiative in the MCU and the Secret Avengers in the comics.
Nick Fury would love Batman for the same reason Jim Gordon does: he's quite an asset. The Dark Knight would be S.H.I.E.L.D.'s main ally and Wayne Enterprises would even fund this organization if needed. Fury would sleep easier at night knowing Batman is out there.
6 Spider-Man
Spider-Man often feels like the anti-Batman. He's kind, funny, and always optimistic, while Batman's broody attitude can be off-putting. However, they're very similar when it comes to their intentions: they believe in justice, but not in pointless violence. Given this, even if Batman isn't charismatic, Peter would still recognize Bruce as the incredible hero he is at heart and he would love him as a role model.
Additionally, Spidey would find Batman's whole aesthetic and mysterious vibe incredibly cool. He would love to test his technology and maybe get a new set of web shooters directly from the Bat Cave.
5 Black Cat
Comic readers know that Felicia "Black Cat" Hardy and Selina "Catwoman" Kyle are very similar: they're both cat-themed burglars, and they have a complex love-hate relationship with a hero—Spider-Man and Batman, respectively. Black Cat could easily fall for Batman just like Catwoman did.
Felicia's relationship with Peter was always complicated because she fell in love with the mask, not the man. She would respect the fact that Batman believes in his duty above anything, and she would probably love the mysterious vigilante even more than his public persona.
4 Iron Man
When it comes to finding Batman's Marvel counterpart, the fandom often comments on Iron Man. After all, both Tony Stark and Bruce Wayne are geniuses and billionaires, and they have no superpowers. Besides, they have a very public playboy persona—even if Batman's identity is a secret.
Nobody else in the Marvel universe has as much in common with Iron Man as Batman. Given this, Tony would like Bruce immediately. They would probably butt heads when it comes to working as a team, but still, there are plenty of things they could bond over.
3 Ms. Marvel
Following Kamala Khan's death and after it was revealed she's a mutant, many things are bound to change in her life, but not her attitude towards other superheroes. Ms. Marvel is still the biggest fangirl, so meeting Batman could only end up with her becoming the Cape Crusader's biggest fan.
Kamala would love Batman simply because he's cool. He's a mysterious guy with dozens of incredible gadgets, plenty of younger allies whom he never underestimates, and an inspiring crusade against crime. He's everything Ms. Marvel aspires to be.
2 Daredevil
If Daredevil and Batman ever met, they would realize they are very similar. They have a no-kill rule, they fight crime as a way of atoning for their past, and they rather lurk in the shadows until they have the perfect chance to attack. Their similarities go beyond the battlefield.
Daredevil would definitely hold Batman in high esteem. He would consider him a valuable asset and—if Batman allows—a dear friend, especially because they would have plenty in common, such as their commitment to crime fighting, their tortured past, and their broody attitude.
1 Captain America
Both Captain America and Batman are incredibly popular, but the fandom tends to ignore how similar they are under the idea that Batman is more like Iron Man and Captain America is more like Superman. However, they fail to realize Bruce and Steve share the same core values.
Upon meeting, Captain America would realize Batman is the perfect ally, and the Dark Knight would earn his respect immediately. They would bond over their tactical expertise and the fact that they both believe in justice, but not in authoritarianism. Batman would probably think of Superman when chatting with Steve.