Brain
Steve Mould, Smarter Every Day, Real Engineering, Vsauce, NightHawkInLight, NileRed, How to Make Everything
Food
Joshua Weissman, Guga Foods, Sous Vide Everything, Andy Cooks, Uncle Haji's Kitchen, Tasting History with Max Miller, Babish Culinary Universe, Yueng Man Cooking
Chill
Serpa Design, MD Fish Tanks, Ben's Worx, NileBlue, ClickSpring, The Samurai Carpenter, Kris Harbour, Just Alex, Ly Thi Ca, Hoàng Huong, Primitive Skills (these last 3 are silent channels from Vietnam. I've linked them since these are hard to search for in a sea of that type of content)
Entertainment
mrnigelng, Will Stelter, Thack Ironworks, shurap, Frog Leap Studios, Andrew Huang, Rob Scallon, look mum no computer