In DC Nation, most of the Outsiders fit this like gloves. Travis is a street kid turned Green Lantern who sometimes forgets there are actual people involved when he starts planning. Green Shield has the Arrow family's moxie with a side order of caustic sarcasm. Caleb and Amelia Zukov love to put up a good show of not giving a shit about their teammates, but God or Hell help you if you if you go after the team...especially if Caleb doesn't particularly like them.
Hashimoto Daichi in Greek Ninja. He's arrogant, selfish and self-centered, and yet somehow... he's not.
Strong Bad from Homestar Runner. He tries to cheat to win contests, bullies around his brother Strong Sad, and left Cloud Cuckoo Lander Homsar for dead, but he does get along well with his co-stars.
Matthew Santoro is this in his early videos. He's usually not very nice to Hugo, but he decides to change his ways and gives Hugo a hoodie with his name on it for Christmas.
The "Misunderstood D-bag" meme is all about this; describing a behaviour usually associated with douchebags or generally unpleasant people, then giving a reasonable explanation that frequently makes them a good guy.
The Nostalgia Critic. He ridicules old movies and TV shows, shoots characters who get on his nerves, and though enjoyable to watch, definitely isn't a nice guy. When he goes to rip up "Follow That Bird", he spends most of the review squeeing like a Fangirl over all of the characters, finally culminating in this loud declaration:
NC: I CAN'T DO IT! I CAN'T MAKE FUN OF SESAME STREET! IT'S THE FIRST SHOW THAT I EVER SAW! [...] I LOVE YOU ALL! YOU'RE SO BEAUTIFUL AND INNOCENT! YOU ARE CHILDHOOD!
He then proceeds to cry, run away, and pay one of his alter-egos Chester A. Bum to finish the review for him.
And in reality, Doug Walker is nothing like his character. A few people have suggested that because he's so likable and dorkily charming that it rubs off on the Critic and makes him more 'heart of gold'-y than what was intended.
And shall we put his Distaff CounterpartThe Nostalgia Chick up here too? She's condescending, has her moments of being utterly deranged, abuses her best friend and hides all of it behind an overly cute, girly persona. But she nearly always tries to find at least one good point in the crap she reviews, she's smart as hell, she clearly thinks Nella's adorable like the rest of us (just have a look at the ends of her "My Little Pony" and "Ever After" reviews) and, as is with Doug/Critic, Lindsay's likability shines through easily.
Really, aside from the obvious evil characters (Ask That Guy, Sage, Mechie), we could put the majority of That Guy with the Glasses here.
Hell even Bennett the Sage seems to have two sides to him. He ACTS like he's the Devil (And doesn't know for sure from time to time whether he is or isn't) to people like Jesotaku, the Nostalgia Critic and Linkara, but beforehand had an Anime Abandon with Linkara out of goodwill and even indulged him on a few things, and his Eva Abandon review ended with him need revalidation from someone else.
Linkara kind of averages out somewhere around here. He can be a jackass, a cheat, a liar, a bully and just generally a tool, but still cares deeply for the spirit of his magic gun, and at least tries to do the right thing.
Church from Red vs. Blue is surly, rude, and generally hates everyone around him. On occasion, however, he shown he genuinely cares about his friends, going as far as to utter a Big "NO!" when Caboose - a character with an IQ of -12 who had done nothing but annoy him since they met - when he was killed (he got better). In the season finale of Reconstruction, he sacrifices himself so his friends can escape.
Its more than that, Church could have easily escaped with the rest of the Reds and Caboose, but stayed behind to help Washington, who he seemed to dislike more than anyone because of his freelancer status. Because Church would be destroyed by the EMP, staying behind meant certain death whether or not Wash succeeded. Heroic Sacrifice indeed.
While we're at it, Wash belongs here as well. He's a genuinely good guy who's just had the crap kicked out of him by the universe, to the point of extreme cynicism. The first time(in some great amount of years) he's shown genuine affection by the Blood Gulch crew, he's stunned, and from that point on, is a solid good guy.
In Season 12, Felix takes a level in jerkass, constantly berating, snarking, and abusing the remaining members of the Blood Gulch Crew, as opposed to his starry eyed fanboy treatment of them before. However, this is only because he knows they aren't prepared for war, and wants them to be prepared for when they have to face Locus and the Federation. He still cares deeply about them, and it's implied he also cares about Vanessa and her rebellion, though he takes great steps to avoid showing it.
Except, as Episode 10 reveals, no, he doesn't. At all. He was Evil All Along, and working with Locus to get the Federation and the rebels to kill each other off. He absolutely hates the Blood Gulch Crew, and despised every moment he had to spend with them. He even mentions this trope by name, and laughs at them for believing it to be true. The fanboy act was a ruse to get information out of them so he could help Locus coordinate an attack on their crash site, and he doesn't care at all about Vanessa or the rebels. He then tries to gun the entire team down in cold blood with disintegration weapons so their story can never be told. Wow.
While we're talking about Rooster Teeth productions, we have Weiss from RWBY who has a razor sharp and unrelenting tongue, but at the end of the day is shown to care about her teammates. Her initial bickering with Ruby has turned to them being vitriolic best buds and Blake's being an ex-member of the White Fang? After some time to cool off and think about it she decided she just doesn't really care.
When we finally meet Uncle Qrow in Volume 3, he definitely is a straight-cut example of this trope. He's a surly, acerbic alcoholic who trashes Atlas robots for laughs and displays Brutal Honesty to the point of outright rudeness. However, it's very clear from his interactions with his nieces that they're his entire world. He even sits down and plays video games with them, and gives them cute nicknames!
We also meet Weiss' older sister, Winter. Even though Winter is a bit callous and aloof (even Dope Slapping Weiss at one point), she cares deeply for Weiss and acts as a mentor figure to her, even teaching her how to use her summoning Semblance.
Sean "Lucky" O'Cann of Survival of the Fittest acts like a bit of a prick, but has been shown to be genuinely warm and affectionate at other times. It's how he deals with his insecurities, for the most part.
Kodiak of the Whateley Universe. He chases girls, he pushes people around, he was in the Alphas when Don Sebastiano ran it. But he's been looking for Ms. Right and is sticking with her; he pushes people to see if they'll stand up to him because he has the spirit of the bear giving him superpowers; and as soon as he could kick Don Sebastiano out and fix the Alphas, he did so, even though it meant he could lose his spot as the head Alpha in doing so.
Steg, a popular YoutubePooper, says that although he seems to act quite angry on the Internet, he's pretty nice when you get to know him. And he has a sense of humour.
Played with in Ultra Fast Pony. Pinkie Pie deliberately invokes this to convince the prickly loner Cranky that he actually likes her. It doesn't work. (In the context of the whole episode, Cranky comes across as less of a jerk than Pinkie does.)
Cranky: I hate you so much. Pinkie: Oh, come on, Dixie, that's just your brain talking. You gotta listen to your heart! Cranky: My heart also hates you so much.
To be fair, he was not the jerk in that scenario to begin with.
Carmilla. She may be a rude, aggressive vampire who has spent centuries as The Dragon to the Big Bad, but she really does care about Laura and her friends. Notice how frustrated she was when LaFontaine was kidnapped, and in season two when Perry walks into the room clearly traumatized and smelling like blood, Carmilla gets to her feet immediately just like Laura does.