In no particular order:

The Royal Institution (https://youtube.com/c/TheRoyalInstitution)

Team Coco (https://youtube.com/c/TeamCoco)

World Science Festival (https://youtube.com/c/WorldScienceFestival)

Sabine Hossenfelder (https://youtube.com/c/SabineHossenfelder)

3Blue1Brown (https://youtube.com/c/3blue1brown)

PBS Space Time (https://youtube.com/c/pbsspacetime)

Tuesdays with Stories! (https://youtube.com/c/TuesdayswithStories)

Perimeter Institute for Theoretical Physics (https://youtube.com/user/PIOutreach)

Science & Cocktails (https://youtube.com/c/ScienceCocktails)