Most Helpful Girl
I have an eclectic taste, but these are some channels I frequently watch:
Geek & Sundry
Screen Junkies (Honest Trailers are sometimes really funny)
Chronic Gamer Girl
TheSw1tcher (Matt & Pat Two Best Friends Play, sometimes Super Best Friends play through are funny)
Most Helpful Guy
HarshlyCritical - watch his playthroughs.
ExplosmEntertainment - for the funny cartoons.
NigaHiga - for the funny skits.
OneyNG - for the funny and insanely weird cartoons.
RedLetterMedia - for the movie reviews.
smudboy - for video game analysis.
Alltime10's and all of thier subchannels - for the interesting stuff.
Vsauce and it's two subchannels - for the interesting stuff.
Thaughty2 - for the interesting stuff.
VariantComics - for the interesting stuff.
AlternateHistoryClub and GeographyClub - for the interesting stuff.
MinuteEarth - for the interesting stuff.
Nerdist - for the interesting stuff.
I have a few more but these were the best.1