"Run's dead." for any minor infraction in his runs.
"YOU DISINGENUOUS DENSE MOTHERFUCKER, OBVIOUSLY YOU HAVE TO KNOW SOMETHING ABOUT SOMETHING OR YOU WOULDN'T KNOW HOW TO TIE YOUR SHOES!" was just meant to be a one-off phrase directed at TheQuartering, but it ended up becoming a huge meme for the sheer Sophisticated as Hell passion behind it. Matt gladly accepted it.
Matt is orange.Explanation A selfie from Matt (seen on the main page) went viral in his community for the weird lighting causing his skin to appear orange. Cue many jokes that this is his natural skin color, or that any character with orange skin is in fact Matto.
Michael was not in witness protection.Explanation Matt made a video explaining in detail why Michael was never in witness protection like many GTA V fans tend to claim. While the video is appreciated for clearing things up, his demeanor in the video has led to many jokes and memes implying that anyone even remotely suggesting otherwise is a major Berserk Button for Matt.
"MERRYWEATHER FLEET'S HERE, BRO!"Explanation A phrase repeated ad nauseum by Trevor during a particularly tiresome episode of Pacifist%. Because of the amount of combat the mission (Derailed) involves, it is extremely hard, if not impossible not to kill at least a few people to progress in the mission, especially since Michael cannot hold all the Merryweather goons off himself. Hence many retries which result in hearing this phrase over and over again.
Griefer JesusExplanation One of the many effects seen in the Chaos Randomizer mod for GTA V is the spawning of Jesse, an NPC that looks and acts like Jesus Christ, on the infamous Oppressor Mk. II trying his best to ruin your day. He's become a Memetic Badass to the fandom and The Dreaded to Matt himself.
"THERE AREN'T COUGARS IN MISSIONS!"Explanation During OHKO, Matt was ambushed by a cougar while sniping bikers (Mr. Phillips). His incredulous response and the rarity of cougars spawning in missions soon became a Running Gag within the chat.
"FOURTEEN PAGES!"Explanation In the making of his "Why React Content Harms Everyone", it caught on in the wider YouTube space after he posted his fourteen page script as a way of getting across the video's message before making it. Matt's incredulity at the sheer number of reaction content makers acting like a fourteen page document was an unreasonably long read resulted in "FOURTEEN PAGES" becoming a channel in-joke.