The one that you will go and sit with and be with and not just read about.
Books are dead, an authentic teacher is something alive and responsive to you. They will be your bridge to the real dharma, which is something beyond mind, jhanas, and anything else you can define or read about. If you understand this then of course books can be useful too. But, this is really a danger, there are many teachers that are intellectually stimulating to read and watch as videos but this doesn't mean they can really be in nondual presence with you.
Sorry, just wanted to emphasise this point, but I am sure others will actually answer your question.
“If you propose to speak always ask yourself, is it true, is it necessary, is it kind?”
― Siddhārtha Gautamataichihastings.com