Batman: Batman's entire Rogues Gallery stands out as jerks, but The Joker, unsurprisingly, is also one. Because whenever he's not killing people, he's either taunting them or trying to get under their skin.
There have been moments where the writers make the man himself into one of the most uncomfortable human-beings in comic-history. Combined with his semi-successful attempts to solve his issues, fans commonly accept Batman to be a brat to literal god-like beings!
Guy Gardner's characterization around the time of Crisis on Infinite Earths mainly consisted of being a belligerent jackass who constantly insulted Hal Jordan and John Stewart due to believing he's a better Green Lantern than either of them. 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 complete asshole who pisses everyone off and alienates his allies, which explains why he always seems to be having to make amends with someone.
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).
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 Superman is never so much as mentioned up anywhere else in the comic.
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).
He once offered a huge sum of money to a married waitress to be his mistress for a year for the sole purpose of leaving just before she comes to a decision. It was all just to mess with her sense of morality and leave her never knowing what choice she ultimately would have made.
Circe is traditionally a cruel, self centered egotistical jerk who enslaves and forcibly transforms others into her slaves and sees all of humanity as resources that she finds annoying at best in their current state.
Wonder Woman (1942): Nina Close's husband is abusive, cheats on her, and brushes off anyone who questions him without hiding that he considers himself their superior and everyone to be beneath him. When Nina snaps and kills him it's quite understandable.
Wonder Woman (1987): Bruct—the Sangtee Emperor's replacement D'Tasloo Parva after the capture of A'iir—is a misogynistic bigot who manages to make the Emperor look like a nice person, and is not only gleeful about slaughtering innocents to force the rebels into an obvious trap to try to save them he's also quite happy to pull a gun on his own Emperor to prevent their capture, showing no loyalty to anyone but himself and suicidal overconfidence and arrogance.
The Flash: Eobard Thawne's defining trait isn't just that he's a supervillain, but he's also a petty, dog-kicking asshole on top of it. He goes out of his way to use his time-travelling abilities to either Retgone or ruin the lives of anyone who so much as annoys him, particularly his Arch-Enemy Barry Allen. It isn't enough that Thawne murdered his mother and framed his father for the crime, he also has to go out of his way to do things like causing Barry's homework to blow away or screwing up his baseball game.
Captain Boomerang stood out as a Token Evil Teammate amongst a team of Boxed Crooks not because he was the most evil or ambitious, but because he was the most unpleasant person to work with. A Politically Incorrect Villain with a penchant for backstabbing and cowardice, Boomerang was Hated by All. It’s almost impressive considering he’s a simple bankrobber in a team filled with mercenaries, monsters and the DC universe’s biggest scum.
Doom Patrol: One of the members who joined the team during Paul Kupperberg's run is Karma, who is consistently depicted as a total asshole who spends most of his time insulting his teammates for no reason.
