I think the one that grinds my gears the most is Bellular. I remember a few years back when he was new he seemed to make fairly neutral videos on things happening in the game that I watched for the news in them - like new things added to the game or what was happening. However at some point his channel just became this brain dead circle jerk of hate and clickbait titles. Videos like "Can patch X SAVE WoW?!", "The game is on its last legs" and so on, you get the point. I always find discussion interesting and I'm never interested in the insanely exaggerated opposite ends of the spectrum where you either get videos praising everything OR videos shitting on everything. I think discussion is interesting to see why X is bad or Y is good and I felt very little of that from his channel in the last few years. He just comes off as someone who hasn't really been playing the game but he stays in the loop and takes any sign of trouble and blows it up 300 times to get a scoop and some clicks on his videos.
I used to dislike Asmongold based on his persona but having seen a few more videos of him I have grown to appreciate him a bit. He has some of the worst opinions on the game that I have ever heard (like saying MoP was all bad just because pandas) and I still dislike his meme persona, and I don't really care for anything he does in the game, but I find it interesting to watch his "asmongold reacts to" videos because when he is being genuine and he is giving his real thoughts and opinions I actually think he says some interesting things. It's just a shame it's kinda hidden behind this persona.