Best Channels
CGP Grey: Explanations about the world, often pointing out important quirky details, high information accuracy
WonderWhy: Explanations about the world, mainly geographical, strong standard of multiperspective presentation and fact-based judgment
3Blue1Brown: Discussions of beautiful results and insightful perspectives in mathematics
Ollie Bye: Maps of the progressions of nations and empires
NativLang: Presentations on language, though sometimes not very connecting or cohesive
JelloApocalypse: Makes fun of the satirizable in various media
Extra Credits: Commentary on games and game design (has a cool subseries called 'Extra History', covering historical stories; unfortunately for sensationalism often delivers a significant amount of inaccuracies, but at least usually covers them in their 'Lies' videos)
Qriosity
Best Videos
YouTube about YouTube
Welcome to YouTube
Rube Goldberg Machines
OK GO: "This Too Shall Pass"
A Marble and Magnet Rube Goldberg
Explanatory Videos
Social Security Cards and Numbers
A History of the British Royal Family (one of my favorite videos ever)
A Detailed Analysis of Brexit
The Terms 'Latino' and 'Hispanic'
Time Zones
Persuasive and Reflective Videos
Why the Penny should Die (and a followup video on Canada)
Welcome to Life: the singularity, ruined by lawyers
Danger: Humans
A Series on the Electoral College and its Failures: here, here, here
Alternative Lyrics Videos
I'll Make a Mon Out of You
Ganon's Gone
Bohemian Gravity
After Ever After (on various Disney Themes)
History of the Soviet Union to the Tetris Theme (although they really ought to have been more comprehensive if they want to be able to claim 'complete' prominently in their video title)
Bad Project
April Fools'
Powerpoint Turing Machine
Other Comedy
J.T.Sexkik
how is prangent formed
Curse of The Weggy Board
placeboing
Alex Jones tries a glass of CAVEMAN
Gay Frogs (Alex Jones REMIX)
"If" - Stuttering Obama Remix featuring Trump
Studio C
Clue Murder Mystery Scandal
Death Bed Repentance
Don't Save The Whales
Elevator Fail
High School Reunion Robbery
International Relations
Overdue Military Letters
Photobombing 101
Photoshop Instructor Crosses the Line
Republicans vs. Democrats
Ritalin Flirting
Shoulder Devil
Spidey Senseless
Two Guys On A Scooter
YouTube Democratic Debate