Every superhero universe NEEDS a Superman figure. They NEED that one larger than life figure that Superman is. A powerful being who stands as a beacon for truth and justice and Marvel is no exception. They've had many homages to Superman before: Gladiator, Hyperion, Sentry, and most recently Blue Marvel. But do they fit with Superman truly or are they just all powers and costumes? Let's take a look shall we?
Gladiator fits with Superman as far as powers go. However personality wise he's as far from him as you could get.
Blue Marvel, while an interesting character, I feel truly lacks what it takes to be a Superman. He's got the powers to be sure, the strength, but he hasn't shown to have Superman's stand for truth and justice. His drive to never stop fighting until the day the world doesn't need him anymore which may never come.
The Sentry truly was Marvel's Superman in one aspect. It wasn't his powers, but the fact actually did represent the purest form of what a superhero is meant to be, just like Superman. I never HATED Sentry, just I found it hard to like him due to the fact he was even more overpowered than Silver Age Superman if that's even possible!!! I mean at one point they said he could control molecules like Molecule Man! MOLECULES!!!!!! That's WAY too far!!! Now MINOR molecular control is fine, even Ms. Marvel has that which is how she can suddenly change into her costume, but having someone who's basically already Superman with that kind of power who's not fighting cosmic level threats and is dealing with supervillans he should alreadt have NO trouble against? Yeah that's kinda bad.
Now Hyperion is the best example of a Marvel Superman. Yes I've said I don't care for him much as a character, but I love the idea of him. He's Marvel's real Superman no ifs and's or buts about it. He's Marvel's closest approximation of Superman and that's good. A version of Hyperion is in the current Avengers roster and so far? I like him. He's got Superman qualities but they're not just shoved in our faces like most versions of Hyperion are. This is what turned me against him as a character. It's like "HEY! He's Superman but he isn't!". That's fine for a while, but when a character is so blatantly obvious it's annoying to me.
So who is Marvel's Superman? Well technically that would be Namor. Yes Namor. Why? Namor the Sub-Mariner was the first character Marvel ever made, way back in the Golden Age when they were called Timely Comics. However from a non-technical stand point? I'm not gonna say. You be the judge.