marami, pero some of my favorites:
vlogbrothers - Hank and John Green talk about stuff
CrashCourse and SciShow - educational videos about anything. SciShow is of course Science based but CrashCourse is more varies; from Computer Science to Physics to Economics to Mythology
Nerdwriter - Evan Puschak. Art nerd and general awesome person. He talks about art in all its forms (paintings, music, film, etc.) and often deconstructs and analyzes them. Does commentary on current events and social issues too, sometimes.
TED Talks - You probably already know this one. If you don't you should. Amazing people talking about amazing things in their respective field / interest.
Ted-Ed - Educational videos about anything. Really random, some are based on TED Talks above. Sweet animations.
Suicide Sheep - Subscribed for the chill music.
TRONICBOX - guy who does a good job of remixing modern pop songs into '80s-style music Really great. Check out his take on Gotye and Kimbra's Somebody That I Used to Know
Film Theory and Game Theory - Matpat theorizing about film, TV, and video games. Really educational. Some of my favorites are the ones where he tells us "How To Survive the Hunger Games" (Part 1, Part 2) and how the Beast got royally screwed over in Beauty and the Beast (the witch is either just dumb or cruel).
Cracked - I like After Hours and Obsessive Pop Culture Disorder. Humor derived from observations on pop culture.
vsauce - Of course.
Yvette Young - I love her. I mean, look.
...and a lot of other music-related channels that would just be too impractical to list.