According to whichever incarnation of the Green Lantern story you subscribe to, how the protagonist who becomes the superhero acquires the all-powerful ring is not the same. In the first origin story, Alan Scott forges his own ring and only uses it as a portable beacon for the power contained in a "magic talking lantern" that fell from the sky. According to the story, the ring needed to be recharged every 24 hours by touching the lantern. While capable of almost anything, the empowered ring couldn't manipulate wooden objects. (So much for using it to help you move out of your apartment.) The second story featured Hal Jordan, a test pilot who received the ring from a dying alien that crashed into the earth. The ring, while open to the imagination, can emit a green beam of light, for both offensive and defensive purposes, that can be used to manipulate objects mentally and physically, create force fields, make objects invisible, as well as allow the wearer to fly, become superfast, and teleport across dimensions via wormhole. It's a wonder why Gollum doesn't clamor after this ring that does a whole lot more than just make you invisible.
Given that the Fantastic Four were all in the same space shuttle, exposed to the same space radiation, you'd think they'd all be physically altered the same way; not so, as they each gained a seperate ability that might say something about each's personality. Johnny Storm, the dare devil by nature, becomes the Human Torch, a living stunt sequence. Ben Grimm, who becomes the Thing, has a hardened exterior, which is greatly symbolic. What can be said about Mr. Fantastic, "flame" of the light-bending (see-through) Sue Storm, and his ability to stretch to envy-inducing lengths? One can only guess at the implications.
Born on the planet Kryton (yet ironically allergic to Kryptonite), Superman was always kind of Super. Upon immigrating illegally to Earth, he found himself able to harness his abilities (speed, strength, gravity defiance, laser vision, etc.). Not so, however, without the aid of the ever-sustaining Sun which acts as a set of jumper cables to his abilities the closer he flies towards it (the opposite, it's worth mentioning, of what was the case for Icarus according to Greek mythology).
All it took was a spider-bite to turn a preppy science nerd into a skull-bashing badass with a tendency for wall-crawling, superhuman agility, and corny quips. Peter Parker is a very duplicitous character, who at once carries the weight of his fragile aunt, a fractured social life, and school work as an ordinary teen and the weight of the world as a force of singular benevolence, ridding the world of supercriminals like the Green Goblin, Doc Ock, the Vulture...and the Tinkerer. Sometimes the dual identities clash as he can only juggle as much as any other superhuman with acne. Then there's the soul-crushing teen angst that no webline or John Hughes movie can cure.
Batman's greatest source of strength is his wealth; without the bank account of Wayne Enterprises supplying his military-grade armor and transportation means, not to mention the myriad Bat-Gadgets kept in his utility belt (a Bat-a-rang, Bat-Sleep, and a grapling hook, to name a few), Bruce Wayne would just be an eccentric billionaire with a rubber suit fetish and crime-fighting fantasies. Instead, he has the goods to keep an entire city of miscreants and madmen in check, those which outshine what the state budget affords your local policeman. As such, it's no wonder Commisioner Gordon aligns with the vigilante, without whom the city would be swallowed alive by the enclosing shroud of rampant darkness.
The X-Men series is a brilliant allegory for anyone deemed an outcast from a society of flawless beings. In that way, the Xavier School for the Gifted provides opportunity for individuals considered unfit for the eyes of the general public. The only prerequisite is that you be a mutant, preferably the kind in which you are able to do superhuman things. That is to say, having more than two thumbs will only make you really good at playing video games. At the school, the students are trained to hone in on their natural abilities, which appear unnatural to the rest of the world. Control is the prevailing idea, but when an evil mutant (Magneto) decides the human race is a toxic species, it helps to have an army of superbeings (with skills like fireball-throwing, laser-eyes, earthquake-causing, and spike-shooting) that are trained to kill in bulk without making too much of a mess. Lessons of xenophobia aside, maybe there is a reason these kind of mutants should be feared. Less-violent mutations (e.g. health regeneration, telekenesis, and super-strength) could at the very least be offered up to the scientific community for the benefit of humanity. But no, mutant battles are the better choice.
Hulk is a tranformative super-hero; while gamma rays may have put a Hulk in otherwise ordinary scientist Bruce Banner, anger is what's ultimately required to trigger the beast within. Anger, to most, might just raise blood pressure or cloud judgement; to Banner, anger is like to Dr. Jeckyl the serym that uncages the murderous madman Mr. Hyde, capable of anything violent and all things physical, incaple of inhibition. While Hulk works ultimately for good and is a part-time Avenger, it's a wonder how his Frankenstein-like propensity for dialogue and reckless, id-driven abandon can be tamed enough to commit a good deed (unless such a good deed involves smashing an evil one to bits).
Wonder Woman is a truly empowered woman, in many senses: she stands for every woman who deserves equal rights and treatment, and she can kick ass like no man can. After all, she was (at least in the original, Greek mythology-steeped story) the best example of the Aphrodite-created race of superior-to-men Amazonian women, unmatched in strength, speed, and wits. And if she weren't a superhero, she'd be a CEO of some male-dominated conglomeration. Or Hilary Clinton. While she has that, she also, like any woman, has a trunk-ful of accessories she must bring with her everywhere she goes, including impenetrable wrist cuffs and a "lasso of truth," which instills a characteristic of honesty unto anyone bound by its amber clutches. Any politician should be afraid.
While he may be the Norse god of thunder, he, like any normal man, requires tools to get the job done. Tools in this case being his "hammer-of-the-gods" named Mjolnir (yes his hammer has a name) which enhances his pre-exisiting abilities, while providing most of his others. He is super-strong and super-fast (a comic book hero given) and can use the hammer to regenerate health and limbs as well as manipulate the weather (kind of like Storm from X-Men). He's not immortal, but eating "golden apples" on occasion allows him to live an added extra couple thousand years. Thusly Thor is part god, part P.S.A.; after all, they do say an apple a day keeps the doctor away.
High-tech weapons dealer Tony Stark got a taste of his own medicine when shrapnel gets lodged in his heart and he is taken behind enemy lines. There he builds a super-suit, because he is also a genious, instead of the bomb he was forced to under captivity. While constructing a superpowerful magnet to keep the shrapnel from entering his heart, powered by a high-capacity fuel cell, he also builds a reactive suit around his gleaming chest, capable of flight, indestructability, and shooting missles and fire balls. Always the risk-taker, Stark regularly disregards his well-being by testing the energy levels (to extreme, battle-weary ends) of the same device that keeps him alive. That and he drinks too much.