Little else appeals to the science geek in all of us then watching things explode or move in slow motion for no apparent reason. Completely charming, intelligent, and self-effacing Gav and Dan make for addictive explosive fare. Their technical resources alone make them an easy watch.
Best-selling author John Green and his brother Hank started a HUGELY popular YouTube community (Nerdfighters) WAY before John hit the big time. They do bi-weekly vlogs to this day and are a suitable mix of funny, impassioned cries for justice, and enlightened pieces of trivia. For some reason they won't let me embed a video, but you can find a good starting point here.
So Jenna Marbles taught us that being a professional vlogger is actually a real thing and you can turn it into a very wealthy business just by making weekly videos of you being a very funny weirdo. Once again, a good starting point is here.
Insanely popular comedian and all-round nice person Amy Poehler hosts a regular YouTube show where she gives advice to young girls or interviews them about the world's dilemmas. It's heart-warming and awesome.
lso, as an extra tip, type in 'Comedians In Cars Getting Coffee' and see a whole web series produced by Jerry Seinfeld that is...well, comedians in cars getting coffee. And they talk about stuff. Awesome.