Science/Math/Tech: Numberphile, Computerphile, Periodic Videos, Sixty Symbols, Objectivity, DeepSkyVideos, PBS Aeons, Adam Savage's Tested, LGR
History/Logistics: Biographics, Modern History TV, Wendover Productions.
Music/Art: 12Tone, Produce Like a Pro, Point Blank Music Academy, HAINBACH, LOOK MUM NO COMPUTER, Rick Beato, Baumgartner Restoration.
Gaming: Summoning Salt, Cloth Map, Did You Know Gaming
Lighthearted/Comedy: Red Letter Media, Good Mythical Morning, Barnaby Dixon, Buzzfeed Unsolved
Cooking: Glen and Friends (love it when they try to re-create 1880s coca cola, the KFC formula, really old translated recipes from books that are falling apart, etc.)