The character Superman, according to his own creators, was originally simply Sherlock Holmes + Hercules, eventually though, he gained the ability to fly, among other powers he got from earth's yellow sun.
I would agry with ugly though, as his observations are interesting; myself I'm a comic book fan too, but not hardcore. I generally read all the "DC" and "Marvel" Universe books and just read the abridged summary of everything. Call me cheap, but I prefer that over buying a new comic book every month.
Now, the bulk of heroes in Greek myth were demi-gods; half god, half mortal. Here are the characteristics of a demi-god;
1) Remember, in antiquity, both men and women, people were much stronger physically, so when a myth says a given hero is strong, they mean they were STRONG, roughly about the physical strength of a grizzly bear. An average, run-of-the-mill demi-god, depending on what mythic god fathered them (usually Zeus),
2) had the physical strength of a grizzly bear, or four large and strong men, they averaged in height about 6'4 or 6'5, weight wise they were only medium built or sized reason being, the Greeks were really into "proportion," so the demi gods were born with naturally good proportions, they NEVER had to strength train,
3) they were born strong and muscular and they could never get out of shape. Imagine having a sculpted body all the time, perfectly sculpted and yet never having to spend a minute at the gym, or spending a dime on supplements. Even a person born muscular, a natural athlete, can get fat; a demi-god though, can never get fat.
4) While not immortal they enjoyed longer life spans, and, they kept the virility of their youth for much longer. For example Theseus, the hero who killed the minotaur, lusted after, and raped, Helen of Troy, but see Helen was 15 years old at the time, while Theseus, according to Greek myth chronology, was born a full 60 years early, meaning he was 80 years old at the time. One of the gifts of having "god" blood, is that you age much more slowly, so even though he was 80, biologically speaking Theseus, according to myth was in fact closer to a male in his 30's. Oh yeah and speaking of sexual assault....
5) Yes, they were superhumanly virile too; Hercules impregnated 50 women in a single night, for example.
In other words, a demi god of greek myth, often had abilities surpassing those of ANY world class athlete, no matter how hard the trained, surpassing those of even martial arts masters, TRUE masters. Additionally, yes, they were born smarter too according to myth.
With the exception of Hercules though, few mythological heroes would do very well against the likes of the really powerful superheroes or even the likes of "smalltime" like Spiderman. I call him "Smalltime" because even though he is normally able to lift about 10 tons, Spidey can only reach monstrous strength when EXTREMELY pressured. Running on anger, or fear, Spiderman has been known to move up to 40 tons. All Spidey would need to do to kill most demi-gods of greek myth is punch their heads off. He would not even need to resort to that though, likely Spiderman would probably just trap them in his web or something.
I would go with the other poster's answer though, the one who made the most thorough analysis as I personally can't think of any. Both Marvel and DC comics superheroes actually far surpass those of mythology with the exception of Hercules who, because the character is strong, he can hold his own against the heavy hitters and in Marvel, Thor actually IS a real mythological deity, or rather, a "real" myth. You know what I mean!