These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Copyright abusers are a huge target of his, in no small part due to their pettiness and abuse of the law. Given how he's been a victim of this many times- and knows many people that are also victims- this is completely understandable.
The Minecraft fanbase, in no small part due to the Fan Dumb constantly pressuring him to play it.
Broken Base: His insistence of picking apart the options menu in many games has split the audience between those who are as insistent on the matter as he is, and those who only want to see gameplay. In videos that go on longer than a half an hour, he will usually provide an annotation to skip right to gameplay.
He holds CD Projekt RED in high regard, due to them developing great games, not using any DRM, and even add a ton of more content in patches that'd usually be paid DLC nowadays. That's on top of their M.O. for GOG (i.e., making it so classic titles that can't run on modern systems can).
In his research stream for Guise of the Wolf, TB remarks that he would find it hilarious if the developers went the route of Day One: Garry's Incident and filed a fraudulent DMCA claim against him. As it turns out, that's exactly what ended up happening. Though this could arguably be more Hilarious in Hindsight considering how badly the company came off looking and were forced to back down.
In a harsher incident, TB's recent product that he sold through Rodeo Arcade was a shirt and poster combination parodying Breaking Bad, making him out as Walter White with the slogan "I am the one who mocks." A pretty good parody until recent events when he was diagnosed with colon cancer.
A lot of people who watched him mainly for the coverage of the Cata beta quit watching him entirely when he quit World of Warcraft.
When people asked him for his opinion on Diablo III and he criticised certain aspects of the game like the memetically infamous "Error 37" of the servers and the fact that it wouldn't have happened if the game had offline capability, he was loudly called out on it.
He actually dares say bad things about certain Indie games with Immunity To Criticism - And naturally if you look at the comments, you'll see a lot of this.
After Total Biscuit made Tweets about how he got a video removed due to using Pokemon footage that seemed to be ripped from Nintendo's official sources, he then linked to a news post on a Nintendo fansite where a few comments were from people disagreeing with his opinions on the matter, and insulting the people who disagreed with him by calling them "children." This caused non-fans of his to start to see him in a rather negative light, especially since said comments were actually in the minority on said fansite, as most were actually agreeing with Biscuit on the matter. The post in question can be found here.
In one of the Terraria episodes with him and Jesse, Jesse tells TB that some people write Slash Fic of them, which TB's reaction is that he doesn't want to live anymore. Come his WTF Is...Super Awesome Wagon Adventure video, where he names his wagon crew based on them, has a event where his character and Jesse falls in love and have sex.
In his Content Patch video on the Nintendo Content ID fiasco, he addresses the futility of comparing video games to other forms of media by saying that in a game like chess, one can adjust the rules without the constraints of an engine by moving the pieces wrong, and said that video games don't usually do that. Fast-forward around a year later, and along comes Tabletop Simulator, a game that features exactly that kind of rulebending as one of its most prominent features.
Suckiness Is Painful: Several people, possibly you as well, will suffer through watching him stumble around The Ball's Portal level. He himself admits that he is bad at logic/physics puzzles and doesn't always enjoy playing them.
Has begun to gravitate toward this since Mailbox 133, where he tells the story of how he has been separated from his wife and stepson for four years and has been attempting to make ends meet for them with his YouTube career since.
It became even more apparent in early 2014, when he deleted his reddit account and stopped posting on the Cynicalbrit subreddit due to the stress coming from interacting with his viewerbase making him concerned for his mental and physical health. Then he got the early signs of bowel cancer. His solution? Keep going, and encourage plenty of potential victims to seek help.