*Disclaimer: Below is a long list of content creators I've found who I think other artists, designers, and/or animators can benefit from watching for educational or entertainment purposes. No-one listed is affiliated with Eric Thomas Studios, and all opinions are their own.
3D Modeling & Art
Has a large catalogue of Blender 3D modeling and animation tutorials, full training courses, and whole projects.
Offers a large catalogue of entertaining, educational Blender tutorials and general artist advice videos.
Offers entertaining Blender modeling and animation tutorials and speedarts, with a focus on game development.
Makes entertaining Blender tutorials and speedart videos.
A channel dedicated to education on indie game development, with tutorials covering everything from modeling and texturing to programming.
Graphic & Web Design
A channel all about creativity. He has tutorials and vlogs on every kind of design field around, and gives a lot of great entrepreneurship advice.
Charli Marie TV
An awesome graphic and web designer who posts videos on design, tools, projects, and general artistic insights on a daily basis.
A massive collection of Photoshop and graphic design tutorials.
A web and UI designer with a channel dedicated to tutorials and speedarts. As well as being a fan for his use of Brackets, he does solid work and makes it entertaining to watch!
2D Illustration & Art
A really fun channel to watch for anyone interested in illustration. As someone firmly set in the digital mediums, seeing her traditional work is always a bit mind-blowing, and she has a gorgeous style!
Draw with Jazza
Possibly one of the best edutainment channels I watch, Jazza has videos going back years, covering illustration, concept art, animation, and more recently, VR and 3D.
The channel of published author and illustrator Mark Crilley. He posts phenomenal illustration tutorials weekly, with a focus on manga art.
An awesome illustrator, who mixes enjoyable speedarts in her beautiful style and vlogs with lots of great insights into art and creativity!
Niku Senpai / Nick Silva
A greatly entertaining concept artist with a phenomenal style. You'll find him often streaming his works live, with a great, inclusive artistic community.
A channel all about art, art techniques, and concepting insights, all given while being pretty entertaining.
Animation, Video Production, & Filmmaking
A channel and group dedicated to better filmmaking. They cover motion graphics, filmmaking, photography, and related things, all in a straight-to-the-point, no time wasted approach.
The self-proclaimed “most entertaining non-boring tutorials on YouTube.” After watching his tutorials on VFX, After Effects, and animation in general, I'd tend to agree with that claim.
A channel dedicated to how-tos on filmmaking, from making good VFX and motion graphics, to tips on the actual production of independent films.
A channel with a massive catalogue of video production and motion graphics tutorials, going back years. Also a great resource of royalty-free music and sound effects.
A channel dedicated to VFX and animation tutorials, with a goal of entertaining.