I used to have moderate interest in some of the YouTube populars years ago, but lately since it's gotten bigger most of them just annoy me.
I'm still a huge fan of Rhett and Link and their Good Mythical Morning show. I watch it now and then when I'm bored.
Jacksfilms I'll watch every now and then. Critikal is a pretty funny guy, as well as Jaboody Dubs. Remi Gaillard I'll check in on too.
Other than that I like to watch Jimmy Kimmel highlights too and the skits they do. Kimmel is one of my favorites, even more so now that all the comments on his videos are from salty Trump fanboys who are saying they hate Kimmel now because all he does is make fun of Trump. I like Jimmy more now.
Other than that though I mostly just use Youtube to listen to music. The channels I did name above are usually only watched as an alternative to Netflix whenever I'm laying in bed.