Both Thief and Black Mage from 8-Bit Theater. Sarda also fits, since he's an omnipotent chaotic Trickster Mentor (an example is when he threw Australia on Black Mage, not only to punish him for being disobedient but also because the resulting wave would destroy the city White Mage was helping reconstruct).
Thief is a more intellectual type of jerkass mainly motivated by greed and feelings of elven superiority, who loves screwing people over with legal contracts and l33t ninja skills. Black Mage is, by all accounts, a smelly sociopathic fat little creep with horrible manners vis-a-vis women, to the extend that (it is said) the universe exists to hurt Black Mage. On the other hand many people would love to kick Thief in the groin face, but ever since he upgraded his class to ninja, he's (nearly) impossible to hit.
Everybody in Sinfest is a jerkass to some degree except Jesus, Criminy, and Buddha, but the worst offender is (surprise, surprise) The Devil. Milder cases include Slick, Li'l Evil, and God.
Slick has become less of a jerk over time, but Seymore has become an exponentially bigger jerk sincce 2010.
Grim Jr. from Grim Tales from Down Below is a Jerkass to his little sister, Minnie, because he is jealous of all the attention she is getting.
Mike from Shortpacked!, although he knows he's a jerk and makes a conscious effort to make everyone else miserable. He gets to keep his job at the store because he sells the most product insurance plans by outright threatening people.
Most of the cast of Something Positive. Davan likes to go up to random children and convince them their parents want to kill them, Jason enjoys trapping people into excuses to berate them, Aubrey and Peejee consider assault of strangers and loved ones to be massively good fun. Kharisma, on the other hand, is currently serving time for a murder she didn't commit...but was bragging that she was going to. And yet someone is trying to make a movie out of it. Mike started out this way, but he became more human and likable throughout; at present, he's about the most sympathetic member of the main cast. Most of the cast claim to become sexually aroused by the suffering of others. At this point in his development, Mike is close to being the nicest guy in the strip, and there are times Kharisma comes off more sympathetic than the main cast; at least she's suffering for her sins. Mike seems to have realized what a bastard he was, and has decided that he needs to grow up and mature. He's the only person to actually make such a decision, with the rest of the main cast staying horrible, horrible people.
The above notwithstanding, most readers actually like him, not just the author. Every evaluation above could be heavily questioned, though Squishydodo (the one whose son is now called "Squishybunbunbunbun") indeed seems to suffer from Stockholm Syndrome.
Reynardine from Gunnerkrigg Court is... difficult to categorize. His introduction to the story involved him attempting to kill Antimony, an act he has yet to show any remorse over. Since then, he appears to be undergoing a drawn-out Heel Face Turn, but it's unclear how much of it is really him and how much is just his Restraining Bolt. Rey is, in turn, surly and pleasant, disruptive and helpful, lewd and respectful towards his owner. (For her part, Antimony mainly keeps his company so she can prevent him from doing any real harm, and because she wants to know how he knew her mum.)
The Hat Guy from xkcd is a good example, asshownbythesestrips (given that he's an Expy of Aram). The Hat Guy's new girlfriend/archenemy also follows this trope.
As the Secretary arc proved, he has a long history of assholery. Proves he's something of a Jackass of all trades.
Dominic, from UG Madness. He has a rival, Permission Sam, who's possibly even more of a Jerkass.
Despite the original intention of his being a straight-man, Zexion of Ansem Retort has grown to be the comic's most prominent jerk ass in a comic full of them. He's helped hijack a plane, embezzled tax payer money on hookers, planted explosives in his patients and generally ruined the lives of most everyone around him. The only person that seems to enjoy Zexion's company is Axel, a psychotic mass murderer (that saved Zexion from impeachment by Phoenix Wright by threatening the judge and jury... after killing three previous juries).
Axel and Darth Maul. Yes, THAT Darth Maul. Namine and Aerith help Zexion in his administration though.
Cassiel is willing to beat an innocent party goer over the head and strip her naked to get into a party to make life difficult for Ash, and destroy Rumisiel. Maybe it's that her uncle is Lucifer that makes her act that way or maybe it's because no one will let her forget it.
Sheldon is an egotistical, arrogant and manipulative jerk who abuses his old friends' trust, even stating outright that they're just 'dumb muscle'. He also seems out to claim as much influence as a driver as possible, kicking people off their own roads in racing gambles and using his muscle to ensure they stay off. Also doesn't take kindly to losing a race/bet - when Ash beats him, he smashes his own car up with a rock to make it look like he was on the receiving end of cheating. Fortunately, he's given a Humiliation Conga he won't soon forget.
Heather has made it her mission in life to destroy Ash because her crush liked Ash better. So far she has failed miserably in all her attempts, which usually amount to beating Ash by proxy.
Trigger-happy Men in Black Agent Jerry in The Inexplicable Adventures of Bob!. As essentially a recurring villain or at least obstacle, Jerry isn't supposed to arouse much audience sympathy. At least Agent Ben gets along with him.
Both Yeager and Artax from Nodwick spend most of their time as dicks. Occasionally they show brief hints of the Jerk with a Heart of Goldwhen Piffany is in danger...but they spend the rest of their time planning horrible fates for Nodwick, as entertainment. This kind of treatment for a henchman is all-but-expected.
Topato Potato from Wigu, who lives in a dimension whose survival depends on how much Magical Adventures in Space merchandise Wigu Tinkle purchases, and is willing to do anything, from beating his father to blowing up entire timelines to keep Wigu interested and buying. He would likely be even more of a Jerkass if his partner, Sheriff Pony, didn't serve as his conscience, if not a particularly successful one.
Every character in Sore Thumbs except Sawyer and his bear is this.
Rayne from Least I Could Do most certainly qualifies. Self-centered, self-absorbed and prone to assholery at the drop of a hat for his own amusement. He frequently crosses over into Jerk With A Heartof Gold territory.
Girls with Slingshots has many jerkasses in its cast, but the absolute queen of them all is Candy, who early on attempts to rape Chris and refuses to forgive him for daring to resist and escape, goes out of her way to sabotage her supposed best friend Jameson's relationship with his girlfriend Maureen because she's in love with him herself, and eventually becomes a professional dominatrix, which is probably the least jerky thing she's done. Her hatred for Maureen culminates in her attempting to sabotage her wedding to Jameson. It backfires. Gloriously.
Toadsuke from Supah Nario Bros crosses into Jerkass territory from time to time.
Half the characters of Squid Ninja, at one point of or other. Even Ikago, although he's usually more Jerk with a Heart of Gold than anything else.
Chex from Checkerboard Nightmare. He seems to be incapable of empathy, and have a loose grasp on reality in general. He only seems to get away with it because of Rule of Funny.
Karkat is characterized as an angry and misanthropic Jerkass, (theoretically) like everyone else of his kind.
Vriska is a particularly horrible example of a Jerkass, because the first thing we see of her is the incident in which she runs Tavros off a cliff with mind control. The fandom cheered when Karkat chewed her out.
In Soul Symphony, Charlie's rants about how his bitter rival, Tom Mustaine, is one. He even wears sunglasses indoors.
Elf Blood has Gipsy, a human sorceress who generally treats everyone like crap unless they hold some sort of authority over her.
Si-Hoo from Orange Marmalade. At his first appearance (technically second) it could easily pass as him being a Jerkass With A Heart Of Gold who's simply misunderstood. Chapter 45 rolled around the corner and, no, he cannot be saved. All of the fans screamed: "he's a douche". He's dancing on a Moral Event HorizonFor the Lulz. His call to Ma-ri, the main character (Iron Woobie, troubled teen) is "Hey, bitch!" and taunts her with the idea of ruining her life, while laughin.
Web Original
Trolls, obviously. Especially types like Gray Jaeger on deviantart who is also like this on Tanuke.com, also Rents of Slapstick Anarchy and Habermann of Metokur.org both count, as well as most if not all editors on ED.
Master Chief. Enough said, really. Travis from the same series has his moments, but is nowhere near as extreme an example as the Chief. Cameron and Cody as well. Mostly Cody.
Too many characters in Red vs. Blue fit this trope to name at once, most notably Sarge and Church.
Gordon Freeman is depicted having this kind of personality in Freeman's Mind.
James Potter in the fanfic series "Adventures with the Potterz." [1]
Global Guardians PBEM Universe: The Aryan is a Flying Brickcrimefighter who also happens to be a white supremacist. He absolutely repudiates violence against non-whites (except, you know, when they are non-white criminals), and saves the lives of non-whites as often as he does whites (he believes that by doing this, he is showing himself and his race to be "good examples), but is nonetheless a racist asshair and is quite vocal about his views on race relations.
Almost all of the good guys in A Very Potter Musical qualify, but Harry takes the cake. He's got an ego the size of the sun, constantly rubs it in the faces of all the other characters, and thinks the fact that he's Harry Potter makes him entitled to everything. By contrast, Voldemort's actually a pretty nice guy. Ron, too, especially since he explicitly says "I know I've been a Jerkass lately" when apologizing to Hermione.
Tom (to Zack): If you get in front of the camera, I will stab you. I will actually stab you!
Encyclopedia Dramatica is all about this. From showing all the spoilers at the top of the Harry Potter page to redirecting you to shock images when you search for "kittens", the wiki is the very embodiment of this trope.
Mario himself has even shown this throughout the show, but it shows up most prominently in Season 4.
Spc.Crota has a tendency to make offensive comments.
Every character in the web series Sanity Not Included is a jerkass, but extra points go to Lyle for having the last name Mc Douchebag tp emphasize this.
