It is really difficult for content creators to figure out how to balance creative storytelling and scientific communication. Here are some channels on youtube that I believe are doing a great job at it. Do feel free to contact me and suggest more!
A division of Vox, they do very compelling work and have engaging hosts.
Science of all kinds. Daily news show and several subject-specific branches (psych, space, kids).
The most beautiful (visual and audio) mathematics videos on the planet.
Hard to define what this is… But it is INCREDIBLY addictingly good and thought-provoking.
A rocket engineer trying to make sure he learns alongside his four children on a daily basis. Amazing slow-motion footage and great explanations of physics.
Natural History done in a way I never thought would be as popular as it has become. It is now an inside look into the Field Museum (of Chicago) and shows what life in the field is like. Includes full-length animal dissections, complete with humorous commentary to deal with the morbidity (and the smell).
A physist who has been at the science communication game since the early(ish) days of youtube. He has a broad audience and has a knack for going viral.
(filmed and uploaded to youtube). Now retired (the title prevented it from being promoted on many publishing platforms due to the language). It is hilarious.
Half as Interesting started out as a recurring series on the first channel based on the concept of turning a set of esoteric Wikipedia pages into videos. Most are transportation (train, plane, car, etc.) themed, which sounds boring, I know.
We can learn a lot from this channel, which manages to rack up a lot of views with only stock footage (and a good script).