When it comes to channels NOT related to UE4 and Game Development… I like to check these ones out.
LinusTechTips - For my PC hardware fix.
GameXplain - For Nintendo game coverage.
Cinemassacare - For Entertainment (Angry Video Game Nerd)
WatchMojo - For Entertaining Top 10 lists.
TheYoungTurks - As one of my news sources.
SciShow and SciShow Space - For Science
CrashCourse - because sometimes I fell like sticking more knowledge in my brain.