This is probably going to be a pretty long list, but I won't mention anything that people have already suggested as of now
Atlas Pro - more focused on geography
City Beautiful - covers aspects about city planning, but he's quite US-centric
Cogito - largely the history & origins of various religions
Cold Fusion - talks about key events in the business & tech world
DW Documentary - might be a loose fit, but basically a collection of proper documentaries published by DW (Germany's public broadcaster)
Exploring History - talks about various historical events, also gives the historical context to some of the issues we face today (such as the Taiwan issue, the rise of Merkel, etc)
Extra Credits - they have various series. Main focus is on video game design, but also have weekly videos about certain historical figures/events and myths
Extremities - talk about and interview the people living in really remote places
Feature History - talks about historical events from the medieval period onwards
Invicta - talks about life in Ancient Rome & covers some military history
Joe Scott - emerging & future tech
Mustard - weird vehicles (mostly planes) from the last century
Neo - largely talks about broad geopolitics & current events as well as some videos on logistics and tech
PolyMatter - similar to Neo, mostly talks about tech & logistics, has some videos about how some countries (i.e. China and Singapore) ended up where they are now, and why they're doing what they're doing
Practical Engineering - talks about how infrastructure (roads, sewers, storm drains, weirs, substations, etc.) works
Primal Space - covers what's going on in the current space race (for lack of a better term), largely focuses on what SpaceX is up to
Rare Earth - short documentary style videos done by Evan Hadfield (Chris Hadfield's son). Honestly probably the best YouTube channel
Smarter Every Day - talks about the physics behind various every day things (and increasingly some not so every day things) work. Recently did a series about how nuclear submarines operate
Suibhne - short animated histories of various countries
Tom Scott - interesting and/or weird places around the world
Wendover Productions - largely focuses on how various logistics networks operate
WonderWhy - mostly talks about weird quirks with various countries, like how the French president is an Andorran prince, how Singapore is probably the only country in the world that was made independent against its will, etc.
Vox - mini documentaries about various science, tech, and social things
CGP Grey
Technology Connections
Up and Atom
Vihart
3 blue 1 brown
Standup Maths
Numberphile
Veritasium