Superheroine costumes only come in two styles: skintight and full-body or skintight and skimpy. This sexualized mode of dress has turned off many female readers; there definitely could be more variety in their costumes, especially since the costumes of their male compatriots are so much more diverse. That same diversity, however, allows certain superheroes to dress as risqué as the average superheroine. It's a double standard that fictional women are criticized for their fashion instead of their characterization but there's no outcry of sexism when these heroes happily objectify themselves in tawdry outfits. The obvious solution to this disparity is not to cover up superheroines in unflattering clothes like their bodies are shameful but to make heroes of all genders dress as slutty as possible.
The litmus test for this list's entries is not whether the characters themselves are attractive (but feel free to debate in the comments) but whether the costume appears unsuitable for a heroic avocation. Basically, that means anybody who looks more at home as the entertainment for a bachelorette party than saving the world from superpowered megalomaniacs. I probably could've filled this list just with heroes who wear only briefs, but that doesn't leave much to write about for 11 consecutive entries (the "do underoos count as outeroos when you're not wearing pants?" routine gets stale fast). Instead you get a wider assortment of garment with strategically missing pieces. Characters wearing torn civilian clothes don't count because they should stop being lazy and get themselves real costumes. Now, let's fight misogyny with misanthropy!
The Bureau for Paranormal Research and Defense's top agent wears a trench coat, much like a flasher. Underneath he wears bike shorts securely fastened with a utility belt, which makes him not like a flasher, although he's still not wearing much. He doesn't wear a shirt, which makes him indistinguishable from the neck down from the guys on the covers of supermarket romance novels (providing they're also fire engine red). Hellboy also wears open-toed boots because he walks on bare hooves. Then why does he bother wearing shoes at all? If he has congenitally chilly ankles, why doesn't he just wear pants like his movie counterpart? Flaunting his torso, gams, and cloven feet may make him feel rakish, but Hellboy is sadly mistaken if he thinks he'll get service at a reputable eatery.
10) Robin, Batman
Dick Grayson's original Robin costume was Exhibit A for Dr. Frederick Wertham's Seduction of the Innocent. Against all its bright colors, the eyes are immediately drawn to the largest area of contrast: Robin's bare legs. The short tunic, briefs, & pixie boots also emphasize this. This costume may be fine in a big top trapeze act, but it's terribly impractical for dodging gunfire across rooftops. The most unsavory part is that scary control freak Batman let his adolescent ward fight crime in that get up. It's only useful as a vibrant decoy for distracting pedophile criminals while Batman does something stealthy. In fact, you're probably on an FBI watch list just for looking at this picture of young Dick. Sorry about that.
9) Colossus, X-Men
This Soviet mutant is really fond of showing off how shiny he becomes when he transmutes his skin into organic steel. The top of Colossus' classic costume tapers at the shoulders and bottom to expose plenty of triceps and side torso. The unstable molecules in his clothes even made his pant legs vanish during his transformation. He simplified that process by just wearing underoos amd wrist cuffs when the X-Men lived in the Outback, which made any battle-damaged costume scenes awkward. When he got a redesign featuring non-disappearing pants, giant panels of said trousers were missing to undermine their addition. Is it any wonder why jailbait Shadowcat kept trying to entrap him into statutory rape?
8) Hawkman, Justice Society of America
Hawkman is the rare superhero who actually wears less than his superheroine counterparts, Hawkgirl and Hawkwoman. His costume is also far less complicated than his habitually retconned backstory. This reincarnated pharaoh/alien cop/globetrotting archaeologist hardly wears anything above the belt aside from his winged hawk helmet & the chest straps that keep his Nth metal wings attached. So he's like a walking Furry (Feathery?) bondage party. He did get a full-body flight suit in the great Hawkworld
series, but how many action figures did that get? None of them! Hawkman's nipples are so iconic that not even the New 52 could cover them up.
7) Martian Manhunter, Justice League
Thanks to his shapeshifting powers, J'onn J'onzz the Martian Manhunter could wear any clothes he could imagine. It turns out he's equally fond of chest straps as Hawkman but has no reason to wear them since his cape has a neck clasp. He also goes a step farther in eschewing pants for trunks in his classic costume. His costume is sometimes explained as a symbiotic plant named Zo'ok after his Pre-Crisis pet, adding an extra layer of intimacy to his attire. Either that or he's just a nudist pretending to wear clothes. Martian Manhunter's original costume is so gratuitously revealing that it still looked like normal superheroine wear when he morphed into a Rule 63 version of himself. Martian fashion, much like its gender roles, is progressively unisex.
6) Vartox, Superman
Sean Connery became an international sex symbol as James Bond. So when DC decided to base a character off Connery's appeal, they went straight for ... Zardoz
?! You know, John Boorman's 1974 dystopian sci-fi epic about population control starring Connery in thigh highs and a red diaper? Go watch it right now. We'll wait. Anyhow, Vartox the Valeronian Hyper-Man looks classier than Connery in Zardoz
as he's already potty-trained and has a Freddy Mercury-esque vest. This outfit is actually more modest than the transparent bathrobe and cowboy boots he dons to woo Power Girl into repopulating his sterilized planet in the Sombrero Galaxy. Vartox wields a nigh-unlimited plethora of hyper-powers, the mightiest of which is his epic pornstache.
5) The Creeper
News anchor Jack Ryder becomes as a jaundiced as a Springfieldian when he transforms into the insane Creeper via sketchy experimental science. His outfit was originally an impromptu disguise he used to get into a costume party to spy on Dr. Yatz, whom he became a guinea pig for. Anyone who can throw together a costume made from yellow tights (which somehow became yellow skin), a green wig, a striped banana hammock, and plenty of red fur on a moment's notice obviously has a kinky wardrobe. The aggressively weird Creeper possesses a handful of superpowers like a laugh that's literally painful, but his real superpower is being able to move under the weight of the world's largest fur boa.
4) Hercules, Avengers
Just as they did for Thor, Marvel also conscripted the mythic Hercules into the Avengers. Like classical depictions of the Hellenic Demi-God, Marvel's Hercules doesn't believe in hiding his mightily thewed body under layers of clothes either. He's usually more comfortable in a royal sash & skirt, though he's also been known to wear briefs & a studded H-shaped chest harness to appeal to He-Man fans. According to Deadpool, Hercules doesn't wear anything beneath that skirt. That paradoxically increases the demand for fan-service pictures of him while guaranteeing that none ever appear in an official Marvel comic. Hercules also wears really complicated sandals that go as high as hooker boots. What do you even call those things? Boodals? Sandoots?'
3) Namor the Sub-Mariner
If Spock had tiny wings on his ankles, ruled an undersea kingdom and was perpetually in pon farr, he'd be the Atlantean prince Namor, a.k.a. the Sub-Mariner. Namor's most recognizable outfit is basically a scaly green speedo and blinged-out accoutrements. Sometimes he wears a special outfit to help his hybrid Atlantean physiology survive on dry land for extended periods. Instead of getting a cumbersome containment suit, he had the royal engineers/tailors whip up something that makes him look like a leather daddy (with underarm wings). The amphibious suit would probably function more efficiently if he zipped up his vest, but then how would he sexually harass the Invisible Woman with his abs?
2) Cosmic Boy, Legion of Super-Heroes
The magnetic co-founder of the Legion of Super-Heroes started off wearing pink and black tights because people of the '50s thought unitards were the wave of the future. Cosmic Boy was frequently mocked by readers for wearing a traditionally "girly" color. When Mike Grell took over art in the '70s, he tried to make Cosmic Boy appear more masculine by removing the pink from his outfit and replacing it with ... nothing. Grell's rationale was that 31st century sexual equality demanded that Legionnaires of both sexes flaunt their flesh. So Cosmic Boy wore a bustier (possibly made with paneling from the bones of the space whale that gave teammate Ultra Boy his powers), which suggests that Rocky Horror Picture Show
will survive a thousand years. The redesign actually helped sell the idea of a futuristic culture since nobody could dress like this in public even during the '70s without being constantly ribbed about it. After Grell left, Cosmic Boy began wearing purple and black variations of his original outfit out of prudish '50s nostalgia.
1) Dr. Manhattan, Watchmen
When Dr. John Osterman became the nuclear superhuman Dr. Manhattan, the government wanted him to wear a helmet bearing an atomic symbol and a tank top. Instead he just etched the symbol for Hydrogen directly into his noggin (a.k.a. "The Bronx"). Then he used his clairvoyant omniscience to hear Right Said Fred early and decided that he was also too sexy for his federally mandated shirt. By the time he singlehandedly won the Vietnam War, he was down to his skivvies. Mind you, these weren't just an off the rack pair of underpants. These were unusually angular briefs with the center of the waistband cut out to point directly at "Lower Manhattan," a.k.a. the "Meatpacking District." This gives him the edge over other freaks of science clad only in underpants like Beast and the Thing. He'll even grow several stories tall just in case you couldn't see how scantily clad he was from where you are. Now he just levitates around naked as a bioluminescent jaybird to spare you the subatomic effort of mentally undressing him. Dr. Manhattan claims to be above human concerns like basic sartorial courtesy, but he's really just an aloof exhibitionist.