Helloween4545, dear ol' Helloween... Been following him for years. It's a small, basic little channel and all the sweeter for it. It's fun seeing LPs of games I don't particularly want to play, but rather like learning more about.
His main content is horror games, and he has been rather desensitised over the years, and was probably not easily frightened from the beginning. I just love it when he looks at some horriphic scenery and doesn't even bat an eye. Or the precious few times when he really does get scared.
I also love the Yogscast. Not the most refined thing to admit, considering the core fanbase is likely much younger than me, but again, it's just some damn good fun. The sheer scale of that channel gives them alot of elbow room to do fun stuff for its own sake.
For me, they fill sort of the same role as Top Gear. I'm not particularly interested in their skills at the game (such as they are), I'm just there for the tomfoolery and the inevitable disasters. The humour is rather blunt, but that's good enough for what it tries to be.