Jenny Nicholson, Horse Girl. Does a lot of long videos on various topics. Amusement parks, Bronies, The Vampire Diaries, etc.
I love Jenny Nicholson. You don't need to have to be a fan of any of those things to enjoy her stuff. It's just very smart, very droll commentary on pop culture. I can listen to her talk about anything.
My favorite channel, though, is Drawfee. It's basically improv comedy in the form of sketching. This one is probably my favorite.