Kurtjmac barely ever swears, preferring "crap" and "nuts to you" and occasionally dropping a "hell" or a "damn". In the most recent episode of the Mindcrack Ultra Hardcore series (in which well-known MinecraftLet's Players duke it out last-man-standing-style while running a difficulty-increasing mod), he goes from full health (and a very complete player-killing kit to boot) to dead, in less than a second, by glitching into a block because his (four) dogs teleported to him while his boat was near land, in memory-intensive terrain, on a laggy and crowded server. His response? "Motherfuck-" *cut to old-timey We Are Experiencing Technical Difficulties slide*
The earlier episodes of Lonelygirl15 were like this. Bree swears precisely once in the entire series, in "I Probably Shouldn't Post This...", when she is defending the Hymn of One in a heated argument with Daniel: "It's my beliefs! There's a million fucking different religions in the world!"
Notably, Linkara (who never uses stronger language) actually referred to a character as a twat in his JLA: Act of God review. Also in that review, he uses the word "goddamn," which is all the more appropriate as the comic was partly written as Christian propaganda.
In one crossover review with Bennett the Sage, he had Bennett do the Precision F Strikes for him. Linkara paused when most people would curse, and Bennet said the F-word for him. Immediately followed by a subversion of the gag:
Sage: Are you, uh, done here? Linkara: Bitch, I haven't even gotten started yet.
And then when he made an appearance in Bennett the Sage's Masterpiece Fanfic Theatre in which he was tied to a chair and forced to listen to his own teenage fanfiction, he WOULD have dropped an f-bomb...if Bennett hadn't conveniently gagged him.
He does say "Son of a bitch!" (his strongest swear, aside from a bad imitation of him by The Nostalgia Critic, who made him say the F word in a faked apology video) when he reaches his breaking point, much to Bennet's amazement.
Cry for Justice had him as close to dropping the f-bomb as he'll probably will ever get: "This is a freakin' joke!!!"
Linkara: Add up everything that you have ever done, and what do you have to show for it? Jack and shit. And jack left town.
Someone decided to rant on Linkara's blog about seeing another JewWario video. Linkara (basically the biggest Nice Guy on TGWTG) ended his response with "Fuck you. Fuck you and never come back." This happened AFTER JewWario committed suicide, it's no wonder why Linkara was so ticked.
During Con Bravo D20 Live 2014, Linkara slips up and says fuck while arguing with Big Mike, before correcting himself immediately.
During one of the TGWTG charity Livestreams, Linkara offered viewers who donated more money the chance to hear him say "fuck." Doug pointed out that he just said it, to which Linkara replied, "...no, I didn't."
The best example would be during the final battle with Mechakara during the movie.
Mechakara: I shall paint these walls with your blood! Linkara: Yeah? Fuck you too.
You know you're in deep shit when GOD swears, as The Nostalgia Critic found out the hard way when he called God benevolent when in fact he was vengeful.
God:Your ass is grass.
An O.O.C. Is Serious Business occurs in AJCO when Egg, the quiet teenager who had sworn only once up until this point (and even then she was only mimicking Kube in a friendly fashion), swears at A_J following her removal from the hangar and the news that she will be expelled to the radioactive outside world.
<Egg> F-fine. Fine. I'll take the bullet, or the gas, or the radiation. But at least I was liked. And loved. Unlike you, you heartless bitch.
Used spectacularly in Survival of the Fittest. Yes, while most characters swear like sailors, cute, meganekko, sugary sweet Louise "Lulu" Altaire manages to pull this off. When she meets Lenny for the third time, after he has just killed her friends the previous times, this time she's prepared. She's killed people, she has a gun and isn't afraid to use it.
Lulu: See this thing, Lenny? Now you take your fucking hands off your handgun or I'll blow a hole through your head.
While he prefers the Cluster F-Bomb, his video on NES Accessories had a rare case of a literal Precision F-Strike. When talking about a headset that fired based on voice, he learns you can say anything and it will work. Leading to...
Nerd: FUCK! [hits duck] Wow, I just shot down a duck by saying fuck.
And a more literal example in part 3 of his CD-I review
Nerd: It's time to start dropping some f-bombs! FUCK [bomb explodes] FUCK [bomb explodes] FUCK [bomb explodes] FUCK [bomb explodes]
Nerd:[rage builds up] F...F... Curse! Curse, Goddamn it! Mnh! I used up all my fuck points during the last 107 episodes. I don't have anything new. I gotta rely on the old tricks. [begins to fight the game cartridge RPG-style] All right. Let's try the Cluster F-Bombs. Fuck this fucking piece of shit fucking shit fucker game! [game attacks the Nerd] UGH! Uhh, gotta go for the Precision F-Strike. Oh, how this game lures you in with its appealing gameplay, and charming atmosphere, and then bends you over and FUCKS'' you to Hell!!
On a similar note to the above, Captain Sparklez rarely swears in most of his videos beyond anything stronger than "god damnit", and that's generally reserved for his non-Minecraft videos. But in his appearance on React when the subject was The Farting Preacher, he found out that his theory on the subject was wrong (he had assumed the videos were a church using viral video as a promotional campaign), and commented "I am so fucking gullible". A year later, he dropped an F-bomb when going for the "Try Not to Laugh" video, vowing to "fucking ace it".
And again in "Coffee Tactics". He also throws out the no swearing rule while playing Slender, because he finds it that terrifying.
There is a scene in Blackburn where Mouse, who is usually too classy for a potty mouth, drops one in stress during her Wham Line.
Fred Clark's Slacktivist blog has a great example in Stop Demanding That You Get Screwed, which has 20 or so paragraphs explaining calmly and patiently why healthcare reform isn't a bad thing, then emphasises it by finishing the postscript with "fuck you, you fucking moron".
YouTube microwave show "Microwave Me" fits this trope, especially with the most common variation of the opening tagline. "Hello, and welcome to Microwave Me, the show where I microwave shit so you don't have to!", but beyond that, it's rare for him to use sexual innuendo or swear words more severe than "damn", "hell", or "ass", although this trope is subverted in this case because he considered "shit" to be equivalent to the three listed above, and not up there with words like "fuck" or "cock".
SF Debris isn't afraid to swear in his reviews, but even so, he's surprising adept at dropping laser-guided F-bombs to emphasize certain situations. This is demonstrated when he inserts his own dialogue into the Star Trek: The Next Generation episode "Where Silence has Lease," where black, redshirted Ensign Haskell proves justGenre Savvy enough to realize how screwed he is.
Nagilum: Now would be a good time to learn about death by killing one of you. Riker: Oh, no! Picard: Oh, no! Troi: Oh, no! Data: Oh, no! Haskell: MOTHER FUCKER!
Rogueamp usually has a few of these in his videos, but perhaps his most famous is "SERIOUS FUCKING BUSINESS" from the Network Crime Ransomware video.
Passing Those Who Inspire Me by Matthew Santoro includes one use of "pretty damn good", but no other swearing.
Video Game High School has skirted the line in recent seasons, but in episode 5 of season 3, Calhoun vents his frustration in a particularly non-highschool friendly way at the Barnstormers.
Of the three hosts of How Did This Get Made?, June Diane Raphael is the one least prone to swearing. In the course of their episode on the film Howard the Duck, June claims that there are points where it looks like Howard is trying to fly. Everyone scoffs but at the end of the episode, opt to try and find what June's talking about. June shouts triumphantly when they find exactly what she's talking about (a scene in which Howard is flapping his arms as if trying to fly).
June: Right there! Right fucking there!
Clumsy Chicken usually lets out a quiet expletive when something bad happens in one of the games she's playing. Otherwise, she doesn't swear a great deal.
“It was a cluster fuck!” Abra snapped as she paced around the floor in Clover’s room.
“Abra!” Clover gasped, “If Mrs. Nelson heard you, she’d wash your mouth out with soap!”
“My best work, up in smoke, and we’re still not any closer to getting any essence!” Abra groused as she shifted yet a little more chalk dust out of an uncomfortable crevice. She plopped down on Clover’s bed, arms crossed, eyebrows beetled. “So, how’re we gonna fix this?”