Gabe putting text of increasingly bizarre swear words and phrases every time he dies on said level.
Yahtzee: What's a Mutant Whore?
One of the best moments of improvised, unitized hilarity comes from the DreamwebLet's Play, where Yahtzee and Gabe pretend to be the main character as he talks to a Police Officer about wanting to make friends. It Makes Sense in Context.  The whole tirade ends with Yatzhee lamenting the lack of ability to murder the cop at the conversations conclusion.
Not only wanting to make friends, but underlining the Ryan's (the main character) utter bumbling ineptness when it comes to serial murder. Behold:
Yahtzee: So while we're here, might as well take a walk around... and talk to a policeman. Hi, policeman! I exactly match the description of someone who's been murdering! Hi! Gabriel: I don't suppose you saw that really handsome, important, and famous killer around here, did you? Yahtzee: I heard he's so great! Gabriel: I heard he's really famous and everyone wants to be like him and be his friend! Would you want to be my friend? Yahtzee: My name's Ryan, by the way! Gabriel: I'm Ryan. Are you my friend now? We're friends. Yahtzee: Would you like my cash card? Gabriel: You want to come to my birthday? Yahtzee: Would you like to check my account details? Gabriel: Look at this gun that's been recently fired! Yahtzee: Yeah! It's great, right? Wanna compare guns? Gabriel: I can shoot it really straight now and everything! Yahtzee: Is yours as great as mine? Gabriel: I got this guy in the eye! Yahtzee: Yeah! Well, five guys! Tonight alone! Gabriel: Look at my muscles! I can swing an axe.
The entirety of the Curse of Enchantia Let's Play, due to the complete moon logic of the game.
Of note is Gabe's increasing Sanity Slippage as they progress through the game, culminating in a scene in which the player character pours sun-tan lotion over himself to escape the clutches of a giant disembodied hand.
Many would say that jumping to Mercury with an adult tiger attached to each bollock could largely be considered an impossible task. I've discovered an even more difficult one; I challenge you to find a bigger bunch of mongwielding tossfucks than the arseholes that make up the cast of CSI: Crime Scene Investigation.
Yahtzee: Don't drink so much while you're murdering people.
This panel is specifically the 'Hour of Love' from the Escapist Expo, where Yahtzee and Jim Sterling (of Jimquisition) are tasked to try and say only positive things without exploding. It is an hour of pure gutbusting funny, especially since the audience keeps baiting them. It doesn't last 15 minutes before the Ho Yay kicks in.
Mark Kline, moderating: "I'd just like to challenge my two co-panelists to sort of get beneath the intellectual and to the emotional. Love is a feeling, so I'd like to feel some affection from you, not just a statement, you know? If you can sort of get in touch with your feelings, I think the audience will feel the love too." Yahtzee: [Beat]...Do you want us to start touching ourselves? Jim:Should we start touching each other?
At the series' start, Yahtzee slams Oasis for being comprised of nothern twats, then clarifies that he's allowed to say that because he's from the north. "Well, my mum was from the north. She's a twat."
And then the topic turns to Trek. Ready your flame shields.
Gabriel: I like Next Gen; I think Voyager and Deep Space Nine were huge wastes. Yahtzee: Hmm, well, I actually like Deep Space Nine. Voyager and Enterprise were wastes of time. Gabriel: Fuck you, Enterprise was great. Yahtzee: Well, fuck you back. Enterprise wasn't great. Gabriel: It was great, it was interesting, it had deep canon; also it was the only Star Trek show I've seen that didn't feel like it was written by Mormons. Yahtzee: Also, fuck you in the bum.
On a smaller scale, Yahtzee's growing horror at the things he's being asked to do in the game. Gabriel keeps assuring him that gets worse..
"This is some Project Mayhem shenanigans right now. Shit gets fucked up."
At one point, this dialog happens: "Someone let a dog do doo-doo, dude!"
* beat *
Yahtzee:(In a voice best described as an audio face-palm) I'm gonna kill myself.
In his Let's Play of Young Merlin, Yahtzee announces he's thought about getting a facial tattoo to dissuade him from ever going back to working a retail job.
Gabriel: "You'd wind up doing concrete cutting or....having to wear a mask and have a dude whip you in front of other people."
Yahtzee: "Well, hey, that life is more fulfilling than retail. It basically is retail, only you're cutting out the middleman."
The bit of Laser-Guided Karma that Yahtzee gets at the end of the Doom II - King of the Hell episode of Uncivil War: after lobbing Mancubus-related fat jokes at Jim Sterling's expense, he gets killed by a Mancubus in the final round.
We have the first draw in Uncivil War history after both Jim and Yahtzee die at the exact same time in the Left 4 Dead challenge.