I saw someone post this on Reddit asking for recommendations for YouTubers that they could watch that produced Unreal Engine training content. There were some good recommendations so I thought I would link the reddit post and post the same question here.
Reddit - What are the Best Unreal YouTube Channels?
Here was the list I presented as well, which has a heavy material/VFX focus:
@tharlevfx - one of the best in depth material educators that teaches because he understands the math behind the nodes
renderBucket - teaches obscure rendering techniques like raymarching and HLSL, plus VFX stuff
PrismaticaDev - very practical and usable game dev focused material tutorials and very exploratory
MathewWadstein - great for his WTF Is? Series for any new nodes
Adrien LOGUT - Epic Dev/PCG creator that also has created a tutorial series outlining PCG as he has developing it. Very useful series to watch and in my opinion, the best to watch first for the integral info
Ben Cloward - very robust channel with tons of content covering a lot of topics. Ranging from new to old techniques and using built in systems and custom built material systems all explained in depth
@EvansBohl - very good animation and material info that is well packaged and delivered in a modular way to easily be implemented in a game, or my case, cinematic. I was able to rework portions of the outline shader to have a quadrant based depth dependent stylized multi colored outline in our most recent YouTube video with the help of his videos.