Straightforward LPers:
TheRPGMinx is one of my longtime favorites for her acidic British wit, general skill level, and being an almost sociopathically good liar in deception-based games. I also love
Cryaotic for his sexily smooth voice, chill demeanor, and unpredictable sense of humor.
John Wolfe (the artist formerly known as HarshlyCritical) is great simply for being more serious and honest than a lot of big horror gamers, and for always giving intelligent criticism when he plays bad games. And while Markiplier doesn't often make me laugh like he did when I was younger, I still subscribe to him because he's a genuinely great person who deserves the success he's earned, and I look up to him quite a bit.
Groups: As Pumpkin mentioned, you can't go wrong with the
Super Best Friends -- they're consistently hilarious no matter which combination of members are in a video, and I've come to see them as a more adult and less obnoxious Game Grumps (whom I also still like, mainly for Danny, but I can only stand Arin for so long).
Vinesauce is great for both streams and standalone videos, and you can find both the standard and the utterly absurd depending on whose channel you're on. I'm also a big fan of the Yogscast (especially
the main guys,
Hannah, and
Zoey) even though their best days are behind most of them.
Miscellaneous weird shit: I sub to Polygon just for
Monster Factory, a weekly series with two hilarious brothers pushing the limits of various games' character customization to horrifying extremes and watching the results play out.
BedBananas, meanwhile, is one of the most criminally underrated Tubers I've ever seen -- his videos alternate between fairly standard gameplay clips and extremely well-edited montages that have clearly had weeks of effort pounded into them (some of my favorites being his
Hitman series and his
Fallout 4 trilogy) and can be anything from surreally funny to weirdly profound.