The only YouTube electrician I would entertain is David Savery, as previously mentioned as he does not film for effect and is very knowledgeable. The others I would not employ for free.
Savery is without doubt the most entertaining, knowledgeable and easy to follow for me.
There are some others that seem to try and do a good job, seem diligent and take on board criticism with the view of improving and then there are some that dont want to hear anything unless its positive feedback, promote bad practice and just want to rinse as much money as they can from customers and YouTube.
Personality has alot to do with it for me. Some of the popular sparks on youtube have really droany voices or questionable attitudes towards customers but may possibly show some intuitive quality workmanship. Theres a few I wont even entertain.
John ward for in depth breakdown on equipment, systems, science and historic electrical installations.
Savery for the best on the ground knowledge of working as a sparks, understanding what it is your actually doing and not just copying what you have seen (understanding test results, understanding why an RCD is tripping).
GSH electrical for understanding circuits, equipment, testing and installations.
Efixx for breakdowns on equipment, science and regulations.