"Modders":
__calcium
Games Repainted
kawaiikaorichan
Lady Lunanova
MainMemory

Twitter sucks because of...
Bobposting
Clara Sorrenti/Keffals
DAclassicgamer/DAepikartman
Erin Reed
Gamechamp3000 (more like Game Chimp lol)
KairiHawk
Katherine Gibes/TransSalamander
Lady Lunanova
Liz Fong-Jones
PearlTrans
RosieRoberta
Saberspark
ThatOneCalledRPG
UltimateDSEris

YouTube:
The Act Man
Awesomemay (more like awfulmay, am I right?)
beat fox15
Bringle
CandyEvie/Luvie
Castoon
chaomix
cjya (ugh, bad name!)
The Completionist(ic Thief lol)
ContraPoints
Cybershell
dabhdude
Dovendraw/Extra Daft
Doobus Goobus
DramaAlert
Dumbsville
Fir
Gamechamp3000
GiIvaSunner/SiIvaGunner
h3h3 Productions
iiluminaughtii
Johnny 2 Cellos
Jrose11
Just Stop/Just Go
Kappy
Lady "I don't have that money" Decade
Lily Orchard
Linkus7
Linus Tech Tips/Techquickie/ShortCircuit/TechLinked (How many channels do these numbskulls need?!)
LioConvoy
LS Mark/Splash Dash/Meeting Halfway
Luke Smith
Magic The Noah
Memeulous
Misty Chronexia
Nux Taku
O3
OneyPlays(WithMyEyes)/OneySays
pchaltv
penguinz0/HugeCharles
Plainrock124
QuantumTV
Quinton Reviews
Ray Rants
RebelTaxi
Shyguymask
SmallAnt
SomeOrdinaryGamers/SomeOrdinaryPodcast
SonnyTM
Sr Pelo/Pelo Streams
SSniperWolf
Stryder7x
Super Bunnyhop
TerminalMontage
Top Hat Gaming Man (more like Top Hat Begging Man, according to retrowatcher)
Trash Taste
UltimateDSfan/UltimateHellscape/8BitComms
Vaush
Veridis Joe
Vinesauce and its subchannels
YMS/AnUnkindness/Sardonicast
(Jeez, YT needs quality control)

Misc:
CWC
Encyclopedia Dramatica
Froge/Froghand
lolcow.farm
NedWolfkin
Rebeccah Kruleski/Rebeccah Starlight/StarGiantess/StarGiantPro/Star Giant Productions
Sophie Labelle
Vinson Ngo/Bleedman
Zone Archive/Zone Toons

In conclusion: nearly everyone is terrible!