Goku has been fighting against some of the most powerful beings in the universe. He's gone up against the likes of the Tyrant Frieza, Beerus the Destroyer, Majin Buu, and Jiren. However, save for a few fighters in the Tournament of Power, he hasn't gone up against fellow Superheroes (save for the undead ones in the filler Tournament of the Kai's).
So, we decided to take a look at five superheroes across the Marvel and DC Universe that Goku could take on in a one on one fight and five that he'd need a few more years of training to defeat.
10 Can Beat: Green Lantern
Green Lanterns use the energy in their power rings to create powerful energy constructs. However, they have one major downside: The Color Yellow. While Green Lanterns have learned to work around this flaw, it becomes complicated when your opponent can shoot yellow energy beams. With the power of Goku's Super Saiyan transformation, all he'll need to do is throw a few punches against people like Hal Jordon and John Stewart, and they're down for the count.
9 Can't Beat: Shazam
He has the strength of Hercules, the stamina of Atlus, the power of Zeus, and the Speed of Mercury and the mind of a child. Shazam is already what Goku would be like if he were in the DC Universe (except for the whole being a kid thing).
While Shazam isn't as well trained in hand to hand combat, he more than makes up with in raw strength and the power of lightning attacks. While Goku has taken on opponents that can shoot energy beams, we haven't seen what he can do when his foes can use magic-based techniques.
8 Can Beat: Wonder Woman
Wonder Woman is the most powerful woman in the entire DC Universe, but that doesn't mean she's the most powerful being of all time. The Champion of the Amazons has learned many fighting skills from her people and has immense strength, but she wouldn't stand that much of a chance against the likes of Goku. Not only does he beat her in pure power, but Goku's years of martial arts training has given far better hand-to-hand training that whatever the Amazon's have been teaching her.
7 Can't Beat: Deadpool
So, in Dragon Ball Super, Goku and Vegeta went up against the most powerful opponent in the Dragon Ball verse: Arale. Though Arale maybe a little robot girl, her "Gag Manga" powers were able to over-power the all-mighty Super Saiyan. Deadpool is the same as Arale... Except for being a foul mouth mercenary who can heal from anything. Deadpool may not pose the same physical challenge as Goku, but he can use his powers of annoyance to irritate Goku. Did we also forget he can regenerate and eat a lot of Chimichangas? Cause he really likes Chimichangas.
6 Can Beat: Iron Man
Just because he's a man inside a suit of Armor doesn't mean he can't take a few hits from god-like beings. Tony Stark has built and refined his Iron Man armor for decades. It's gone up against the likes of the God of Thunder, the nearly indestructible Ultron, the Time Traveling Kang, and the Mad Titan Thanos.
Not only does he have is Repulser beams to fight Goku, but he has dozens of gadgets to take on Universe 7's most powerful opponents. Despite these abilities aiding Iron Man, he still wouldn't last that long against Goku. From Goku's immense speed and powerful Kamehameha attack, He's not going to let Iron Man walk all over him.
5 Can't Beat: Dr. Manhattan
Goku may have gone up against Beerus, The God of Destruction, but Dr. Manhattan would make him quiver in fear. Much like Goku's pal Zennie, Dr. Manhattan can do whatever he pleases. He can teleport to a planet in a second, dismantle matter, change his size, and blasts a person out of existence. The big difference between Zen-oh and Dr. Manhattan is that the latter doesn't share the same child-like whimsy as the former. Dr. Manhattan has grown distant from humanity and lacks any compassion. Say what you will about Zen-oh, at least he cares about people like Goku and Beerus
4 Can Beat: Spider-Man
He's the world's most beloved superhero, but that won't be enough against Goku. Spider-Man has gone up against powerful foes like the Rhino and Venom, but Spider-Man hasn't defeated guys who can blow up mountains with just a single punch. Spider-Man does have his incredible Spider-Sense to help figure out where Goku will attack next, but that won't be enough for a man who can strike at the speed of sound. Face it, Tiger, you didn't hit the Jack Pot with this guy.
3 Can't Beat: Thor
Thor is the son of Odin and the God of Thunder. That alone should make him more than a match for Goku. Goku has foughten against Beerus, but he was unable to defeat the God of Destruction, even with the Devine Energy of Super Saiyan God.
Thor's super strength and ability to call down lightning with Mjolner will give Goku a lot of trouble, even if he went Ultra Instinct. Hell, All Thor would need to do his drop Mjolner on Goku, and that would be the end of that. At least it might give Goku the chance to become worthy and lift the mighty Hammer. That'd be cool to see.
2 Can Beat: Batman
Like Tony Stark, Batman has used a lot of gadgets and technology to go up against the likes of Gods such as Darkseid. However, Goku doesn't have a single weakness as other Super-Villains, nor does his tech come close to go up against the likes of the Super Saiyan. Even if Goku gave time to Batman so he can Prepare, he wouldn't last a nanosecond. He is just a man, after all.
1 Can't Beat: Superman
It's the debate that will never end. Goku is a man all about breaking through the limits set on by him by his greatest foes and allies. However, that's the reason why Goku wouldn't be able to defeat Superman. Superman has no limits. This is a guy who survived a blast of that was like 15 suns exploding, a man who has moved the planet all by himself, a man who was able to lift 400 quintillion tons without breaking a sweat. Superman's power is limitless. Sure, He's weak against Kryptonite and Red Sun energy, but Goku is the guy who wants to fight his foes at their best.