oh! Just remembered! If you haven't watch Meredith Stepien's stand-up that is a MUST! MerediddyS
My favorite is: Shaytards. They're a family who vlogs there life, and the kids are super cute! :) I also love DeniseVlogs, she does these like little horror short episode things, she's a great writer! And my 3rd favorite would be, Cecily, she's really funny :) You should definitely watch them.
BertiebertG! He's sooo funny! And his friend's channels, too. (OMGHarrisonWebb, DomDayable, some others) If you're interested in Harry Potter, Bertie Gilbert (bertiebertG) played Scorpious Malfoy in the last DH for the Epilogue. (:
Well StarKid (duh). I personally enjoy The What The Buck Show, but some people find him kind of offensive because he makes fun of basically EVERYONE lol. Ummm Smosh is okay, their last few videos have been entertaining but I personally like their older stuff better. nigahiga is pretty entertaining. wafflepwn has all of the greatest freakout ever videos. Shane Dawson! Uh.... there's lots more but that's what I've got off of the top of my head. I'm a YouTube freak XD