JewWario is excellent when he is explaining the game play; he is my number 1 really, no-one else does such instruction videos on the great but difficult famicom games. The silly bits however are hard to know if they are supposed to be funny. Maybe it is Jewish humour?
Luke Morse is great too, always so happy about every game he plays ; and he has a great speaking voice.
Too many reviewers are unfortunately unable to speak properly, clearly , not too fast, etc... I need subtitles for those people. Please Americans: when you make videos, try to pronounce properly and not speak too fast, so the rest of the world can enjoy it.
AVGN I can't use his videos for anything... After watching, customers would decide against
buying a game... But I still love watching them.
There are some other very good youtube reviewers that show a short gameplay of the game without messing with it. Such as nenriki86 and FamicomGuide.