Guy Gardner of the Green Lantern Corps and Justice League International. Exactly how much of a jerk he is varies (partly due to complicated mental issues), but at his worst he's tolerated mainly because he's useful in a fight (although getting him to stop can be more of an issue). Thankfully, he received some Character Development over the course of a decade and a half, cleaned up his act, and became a Boisterous Bruiser instead.
Ollie Queen, while ultimately a force of good, has never been particularly nice about it. On his best days, he's rude, arrogant, and is always convinced that his idea is better. On most days, he's a sanctimonious, elitist jackass. At his worst, he's a straight-up fucking asshole who pisses everyone off and alienates his allies, which explains why he always seems to be having to make amends with someone.
Namor consistently treats everyone he knows as inferior to him, often engages in hypocritical rebukes of others, and won't stop trying to get into Sue Storm's pants, marriage be damned. And those are the days he isn't hobnobbing with despots like Osborn or Doom or sending giant tidal waves to drown New York City. Even when he is actually doing something for someone other than himself, you can guarantee he'll be a self-entitled dick about it. The only people he's shown being genuinely nice to are old friends from the Invaders Captain America (because being a Jerkass to him truly puts one in their own league) and Bucky (likely due to the guy's Trauma Conga Line), where he makes a half-ass attempt to put up a Jerkass Façade.
Toyota from Y: The Last Man makes a point of being as unpleasant as possible to everyone she comes into contact with, as if sticking swords through them (not to mention cutting Ampersand's tail) wasn't enough.
Deadpool can be a huge jerkass at times. Especially when it comes to blind Al, Weasel and Bob.
Flash Thompson, in his Flanderised characterisation, and primarily during high school. Afterwards, he became the Loveable Jock, and one of Peter's close friends, even becoming a heroic Badass Normal soldier, before being crippled. Even with the Venom symbionts, he's a pretty nice guy, and served as the Token Good Teamate on General Ross' incarnation of the Thunderbolts (though when your teammates are The Punisher, Elektra, Red Hulk and Deadpool, this ain't that hard).
Jean Grey casually abusing her power by switching Peter and Logan's minds (having threatened to do so to Logan, but Peter, being nowhere near the X-Men, had no clue) just because Logan hit on her one time too many for her taste. Peter flatly calls her and the rest of the X-Men out on this, accusing them of being hated not because they were mutants, but because they were complete assholes.
It should be noted that Jean didn't purposefully do this to Peter. She made it so Logan would switch with the last person he wanted to be and that turned out to be Peter. This arguably makes it worse - she decided some random person deserved to be possessed by Wolverine, and didn't care enough to bother checking who that was.
And speaking of Logan, the implications of just what he tried to do with Mary Jane while in Peter's body, just for starters.
Also, let's not forget that Logan deliberately left Scott to die in the Savage Land, just so he could try and get Jean in bed.
Not that mainstream Wolverine isn't one himself. The guy tried to hit on the already-in a relationship Jean Grey, generally is unpleasant as possible without being violent about it, except when he is, and is a gigantic hypocrite who carries petty grudges and calls people on them whenever he can.
Hank Pym's wife-beater status may be mostly undeserved in the 616-verse, but boy howdy, does he earn it here. And on top of being a Jerk Ass, he's batshit insane on his bad days.
Ultimate Daredevil is a complete tool. He's still a good guy, but his methods are a little more extreme and when a disheartened and down on his luck (for a change of pace) Spiderman asks him for advice, he thoroughly chews him out in the rudest, most dickish way imaginable—something to the effect of "You're a stupid little kid who's in over his head. Get out of this business before you get someone, or more importantlyme, killed." Afterwards, several times when Peter came to his aid Daredevil gave him a mild beating and threw him out of the fight. Eventually, when Daredevil hits his lowest point, it's Peter who talks him out of killing an innocent woman just to get back at Wilson Fisk.
Ultimates 3 turns Hawkeye into a melodramatic, gun-crazy Death Seeker. When he goes to Spider-Man for information after "Venom" attacks the mansion, he gets Spidey's attention by shooting at him, paralyses him with a tranq dart, and then leaves him lying in the snow after getting called back by Cap. Man, Spidey gets this from both teams.
Spider-Man: Hey...uh...guys? Little help here?...I hate you.
Even Captain America is an asshole. While the original writer merely made him a jingoistic "1940s-average-Joe" type, with all the fish-out-of-water attitude that came with it, later writers added in racism and sexism, just to make him match the rest of the universe's assholery. He eventually has an Asshole Realization when Peter Parker dies, having done so by taking a bullet for Steve, mere hours after Steve had given him a long "The Reason You Suck" Speech about why he was a terrible hero.
While anything Mark Millar says in interviews can be taken with an entire bucket of salt, he's gone on record saying that this Cap's personality (which he charitably just calls "social conservative") is specifically what makes him cool, in a Die Hard kind of way. Then again, this is the same interview where he compares Cap to Batman in a "He goes in, 3000 people die', and the situation gets resolved" comment, and that no one's ever taken a superhero in the direction he's taken Ultimate Cap, so once more, take it with a lot of salt.
While Lucy might have been the worst Jerk Ass in the Peanuts cartoons, Violet was the worst Jerk Ass in the comic. She constantly abused Charlie Brown both verbally and physically, and once firmly declared that he had no redeeming qualities whatsoever.
Lucy was, however, a bit of a brat. Once she even told everyone Charlie Brown was hitting her when he hadn't, for no reason whatsoever (in a Sunday strip from November '52). She also teases and bullies her little brother Linus without stopping, forces respect out of other kids through sheer intimidation, and uses Charlie Brown's "sessions" at her booth as an excuse to make him feel even worse about himself. And that's not even getting into the annual football gag, which seems meaner every time she does it. Toward the end of the strip, she started taking on a surprisingly nurturing role toward Rerun, softening up some.
Peter David wrote a great story in X-Factor that gave a reason why Quicksilver's always such a tool. He explains to psychiatrist Doc Samson that everyone gets irritated waiting in a long line because someone else's slowness is holding it up. Imagine if everyone on else the planet is like the person holding up the line. That's the way Quicksilver feels.
Nick Furyis this trope. He is a huge jerkass so you don't have to. Nick wavers between this and Jerk with a Heart of Gold. His Ultimate Universe incarnation tends to reflect this trope more, while the mainstream version tends to channel his Jerkass behaviour at appropriate times, and generally is a Cool Old Guy.
Let's not forget Nermal either. He seems to visit Garfield purely to steal his food, rub it in Garfield's face that Nermal's cuter and younger than he is, use his cuteness to steal Jon's affection and con him into giving Nermal food, and after all that still seems to think that Garfield likes him. Thankfully, Garfield always makes him pay for it.
In issue 6, Peter had just been hired and Jameson had decided to treat Spiderman like a criminal. When everybody leaves, Peter asks Jameson "How do you know he's a criminal?" and Jameson replies "I don't. I could just as easily send good press his way. Why don't I? This will sell more papers." Twenty years later he has a nervous breakdown, why? He didn't unmask Spidey when he had the chance. Complete. Total. Jerkass.
Batman (otherwise known as"Crazy Steve"), in All Star Batman and Robin is by far the most asshole-ish incarnation of the character ever depicted. He not only seems to get a kind of sadistic joy out of any pain he causes criminals (as well as any cops in his way), but he kidnaps and verbally assaults Dick Grayson, (who just moments before had seen his parents killed before his eyes), leaves him to fend for himself in the Batcave and then when he finds out Alfred fed him a proper meal, picks him up by the scruff of his collar and threatens him (this is guy who in most other versions is the closest thing Bruce currently has to a father). And all the other superheroes ain't much better (Wonder Woman shoving a male bystander out of her way whilst calling him a "sperm bank").
In the Millerverse version of DC, superheroes are either brutal psychotic (Black Canary, Crazy Steve) or a witless moron that Batman pretty much controls or treats with utter contempt (Superman and Green Lantern). Kind of like the Ultimate Marvel universe without Spider-Man.
This gets to the point where Millerverse Batman/Crazy Steve just randomly insults Superman during a Spawn/Batman crossover penned by Miller. Made particularly bad by the fact that the Big Blue Boy Scout is never so much as mentioned up anywhere else in the comic.
Many of the superhomies from Empowered, especially Major Havoc.
Part of the reason Lex Luthor is such a good villain is that he's not just a Magnificent Bastard of an obsessed, megalomaniacal Corrupt Corporate Executive-turned-President Evil — he's also an asshole to everyone he meets, including strangers, and goes out of his way to treat the people around him like shit for no reason whatsoever. And he doesn't just do horrible things to people either — he's an asshole even when his actions are incredibly small-scale and pointless (e.g., calling Clark Kent "Mr. Lois Lane" all the time for no reason except to be dickish and irritating.)
Jokey Smurf of The Smurfs with his constant pranks.
King Max Acorn in Sonic the Hedgehog, with everything he's gone through, had devolved into this. A big part of his assholishness is because he was raised to follow royal traditions. That also includes using a mystical golden pool with a strange, undefined connection to make his decisions instead of, say, the guy you hired to be part of your Intelligence Agency. Thus, most of his decisions boil down to "because the pool told me to", including but not limited to disbanding your daughter's well-trained team of heroes over his just-recently formed Secret Service and forcing said daughter to marry someone she really didn't want to. When the Cosmic Retcon Button is hit following Sonic the Hedgehog/Mega Man: Worlds Collide and Max was rewritten to have Taken A Level In Kindness, Sonic took this as a good thing.
Another X-Men example in Julian "Hellion" Keller: Arrogant, angry, self-entitled, and just generally a dick to anyone outside his clique. When Noriko Ashida arrived at the school seeking help for her out of control powers, Julian tried to run her off for no better reason than because she'd been living on the streets and looked (and smelled) it. He takes an immediate dislike to X-23 for no real reason whatsoever. Julian can even be a dick to his own friends, yet at the same time fiercely loyal and protective of them. As a result, he does get better after Stryker's attacks on the school, which allows his softer and more noble side to peak through. However he gets angrier again when his hands get blow'ed up by Bastion, and starts to slide towards the edge of the slippery slope afterwards. Lately, though, he's started to turn things around again and get back to being more of a Jerk with a Heart of Gold.