Thread title says it all, list 'em down.

And I do mean follow as in: "I watch their videos" not just "I'm subscribed."

Here are the ones I follow:

ANewHopeee - Catie Wayne's (Boxxy) new channel.

batinthesun - Super Power Beat Down videos (for example, White Power Ranger vs Scorpion from Mortal Kombat)

Britanny Furlan - Popular Viner.

Brizzy Voices - Fictional character impressions.

CaptainSparklez - Minecraft let's plays and other videos.

Cinemassacre - James Rolfe's (Angry Video Game Nerd) channel.

DJ GIG - Electro House / Melbourne Bounce music.

ERB - Epic Rap Battles of History, enough said.

Fine Bros - The Kids/Teens/Elders/YouTubers React series.

Marble Hornets - Slenderman-related web series.

OMGitsfirefoxx - Minecraft Let's Plays.

JerichoAFK - Minecraft Let's Plays.

Palindrome - Minecraft Let's Plays.

LDShadowlady - Minecraft Let's Plays.

Robin Skouteris - Mash-up music.

Tested - Some science/tech/gadget/nerd stuff.

The Gabbie Show - Popular Viner.

TheSyndicateProject - Minecraft Let's Plays (also other games).

Thomas Sanders - Popular Viner.

TomSka - Sketches, animations (ASDFmovies).

VitalyzdTV - Pranks.

 

AngryJoeShow - gaming

CinemaSins - Everything Wrong With Movies

Jim Sterling - gaming with Jim fucking Sterling, son

LastWeekTonight - John Oliver fixing America (?)

Markiplier - gaming

Sargon of Akkad - social commentary

MundaneMatt - pop culture/gaming news

The Game Theorists - theories about games

The Film Theorists - theories about films/TV

The Great War - WW1 recounted week by week 100 years later

Totalbiscuit - gaming

VSauce - science with a cool spin

Skallagrim - swords, knives and other sharp, pointy things

These are the channels I follow most closely, as in, I watch many of their videos. There are other channels I check on, but I don't want to clutter my sub list with things like ERB which updates rarely.

 

La Belle Musique - Music

Chill Masters - Music

MixHound - Music

Antti Marktikainen - Music (Mostly epic)

Alopex AMVs - Naruto AMVs

Not the most extensive list. I had AngryJoe for a while, but I think he slipped a bit. Still good, but when I want to listen, I'll go to his site.

 

I used to watch Angry Joe back in 2011-2012 but then I got bored of his style.

Markiplier is a fun guy, I saw his SCP: Containment Breach series and he frequently does collab videos with CaptainSparklez.

 

Xandrel, Joe's recent Godzilla and Witcher 3 reviews are entertaining, each in its own way. I like watching his stuff. He puts a lot of work into the videos and a lot of thought into what he says in the reviews. And Other Joe's acting is so wooden it's fun to watch.

Markiplier's videos are hilarious because of him. Like his FNAF series. I like the lore, wouldn't play the game, but Mark's freakouts are golden.

 

Couple I've not seen mentioned yet:

MrBTongue thoughtful, if infrequent, videos about games, movies and story telling.

Vihart Mathy things

ZiggyDExcellent Path of Exile content in particular

GetDaved Chill let's plays of mostly strategy games and rpgs.

HCBailey Possibly the definitive old school jrpg let's player.

 

https://www.youtube.com/watch?v=KjKguUGxioQ

That is all.

 

Star City Games - watch archived SCG coverage, versus, and commander videos.

Magic: The Gathering - official MTG channel

The Magic Show - MTG content, plus the set reviews are awesome

Channel Fireball - more MTG content. Some great content makers (LSV, PV), some not so great (TWoo, JWilson)

Geek and Sundry - if you aren't subscribed to this, you're doing it wrong. Felicia Day, Wil Weaton, Sean Plott...

Tested - great channel - who doesn't love adam savage?

SSundee - daily minecraft videos

Crainer Commentates - More mincraft videos.

Lanceypooh - even more minecraft videos.

Arumba - I mostly watch it for the great CK2 and EUIV videoes.

Tradechat - WoW (and other gaming) news presented by a hot gamer girl

Jay Leno's Garage - great car content

Porsche - a channel every PCA member is probably subscribed too, if they know how to use a computer.

Jalopnik - neat car channel

Super Speedsters Rob - Another car channel

/Drive - yet another car channel

Ashens - Great crap toy reviewer. used to watch the shit out of it, but haven't in awhile.

FPSRussia - awesome channel, even if the guy's not a real Russian.

12Medbe - Whose Line is it Anyway clips

Media Cows - Let's plays

FailArmy - fail compilations.

-edit-

one more

AVGN/cinemassacre - the angry video game nerd

 

The ones I keep up with most consistently are probably these:

videogamedunkey - Funny video game channel.

MisterMetokur - Formerly InternetAristocrat. Mostly tears into stupid SJW Tumblr shit.

hickok45 - Very educational gun channel.

Don't Hug Me I'm Scared - Really interesting/weird video series.

 

Pretty much just Roosterteeth - Used to be heavily gaming related, but really it's moved towards live action and animation since everything else is getting its own channel.

 

Screen Junkies - "Honest Trailers" of Movies

https://www.youtube.com/user/screenjunkies/featured

CinemaSins - "Everything Wrong With" Movies

https://www.youtube.com/user/CinemaSins

CaptainSparklez - Minecraft Parodies and Videos

https://www.youtube.com/user/CaptainSparklez

Jacksfilms - Parodies and other Random Stuff

https://www.youtube.com/user/jacksfilms

Fine Bros - Reaction Videos

https://www.youtube.com/user/TheFineBros

These I can think of on top of my head.

 

Last Week Tonight with John Oliver - Brilliant man with a brilliant show on HBO. I'm sure most are familiar with him by now. Picks 1 topic to focus on, usually one of a controversial nature that the media isn't paying attention to and dives deep. Sometimes shows his bias, but for the most part, I agree with a lot of his jibes and his satire is top notch.

Kuma Films - These 2 asians(i think they're Koreans) travel around the country to find people with amazing talents and showcase them on their youtube channel. There are so many amazing people out there its unreal.

Sawyer7mage - Anime/Manga reviewer, I like his personality and his insights often align with my own. He also rarely makes rather random but humorous videos as well as some thought provoking ones unrelated to manga/anime.

Monstercat - Guy who showcases a lot of musical artists in the techno genre. Lots of Drum n Bass, Dubstep, House, etc and even has them all separated into playlists by subgenre.

Vindsvept - Like Fantasy/Emotional music or music reminiscent of Irish themes? You'll love Vindsvept. I really like a lot of their music, so relaxing and calming. I'll admit they reuse a lot of similar...i don't know the musical word for it but chords maybe? But still, they produce great stuff.

 

Just a few I haven't seen mentioned yet:

A few Hearthstone related channels - Trolden, Trump, Hysteria.
OC Remix - Video game music remixes from all genres, both game and music. For more rock-and-metal oriented, I'm also subscribed to LittleVMills.
Carbot - does cutesy animations for Blizzard games. Started out with just Starcraft, has since branched out into WoW, and a few Hearthstone/Heroes of the Storm videos. Focuses on the absurd with a healthy dose of in-jokes.

 

Jack Stickman - funny horror movie reviews

Rob Dyke - I like his Seriously Strange lists, mostly focused on crime and just strange things

tekking - He's makes videos about Bleach (the manga), I like his top 10 lists

Rabbit in red #2- He(?) releases great murder and true crime documentaries

League of Super Critics - A channel of many funny movie reviewers

Amazing Atheist - He's funny despite being a dick, he does more than just rant about political things

Barely Productions - they make funny song parodies that also sound nice (they use actual singers instead of autotuning everything)

Watchmojo.com - They put out really informative top 10 lists about a wide variety of topics

A dose of Buckley - he talks about mainly music and things in the music industry but also things in society, I love his top 10 worst songs lists that he puts out each year

How it Should Have Ended - they put out funny animated videos pointing out how movie conflicts could have been resolved easily

 

vlogBrothers - a nerdy show about everything. I mostly watch John, though since he's become famous it's somewhat less informative and entartaining.

Veritasium - A nerdy science show.

Vsauce - Another nerdy science show.

PBS Channel Idea - Another nerdy... interesting ideas show?

Vihart - Math being realllly interested. Music too.

thechesswebsite - Champions level games reviewed by GMs, mostly. Some opening reviews too. Keeps my chess itch in check for the most part.

Geek & Sundry - I watch only the tabletop shows, which is a boardgame review channel hosted by Will Wheaton, joined by D to Z class geeky celebrities. Also, Felicia Day is awesome.

 

Screen Junkies - For their "honest" reviews.

Auralnauts - Really talented video editors who make entertaining videos.

h3h3Productions - I like the humor.

Preston Jacobs - For the best tinfoil ASOIAF theories.

These are the channels I follow as in I watch almost all of their videos. I'm subscribed to a lot more channels but watching 1 out of 10 videos of theirs doesn't constitute as following them.

 

A lot of the channels I follow have already been mentioned. Here are the few that are missing.

Crash Course: This channel is squarely focused on educational videos. It started with series focused on history and science, but has expanded to literature, economics, and copyright.

Every Frame a Painting: This channel dissects film, focusing mostly on the cinematography instead of plot/characters.

Extra Credits: Game design, game reviews, and series on interesting history.

Magic of Rahat: Pranks. Lots of pranks.

Rym DeCoster: A mixed bag. A lot of videos of panels from gaming and anime cons discussing game theory, game design, and other subjects. A series that is focused on dissecting the anime Revolutionary Girl Utena. And a handful of lets plays.

 

Uh...

Spectrum Pulse - my channel, where I discuss music, art, and culture at length.

I'll edit with the rest of mine later, the list is extensive.

 

Escapist, for Zero Punctuation. Perhaps the greatest video game reviews of all time, though I do think that his older ones (1 year+) are better than his newer ones. Escapist.

 

Many of those mentioned already are on my list, also these:
Khan Academy - educational
Good Mythical Morning - entertaining
Jay Leno's Garage - cars
CGBros - CGI VFX shorts
AWE ME - metalworking
Devin Super Tramp - people having fun, in HD (4K)