NintendoCapriSun can be quite loud himself. Later videos have shown him to be just as loud as Proton Jon and Chugga. One time, The Runaway Guys were so loud, they actually woke up a woman in the hotel they were staying in.
Golgotha from Noob, especially when one realizes that she's actually inside in real life and not in the open field in which the player avatars are seen running around.
Simon Lane of the Yogscast takes the cake even by his group's standards, often disrupting other people's recordings because he's screaming from several rooms away, once setting off a car alarm outside. Yogtowers is in an office block and a few floors off the ground.
Frankie MacDonald, a Canadian V-Logger uses this style exclusively in his weather reports, which have made them quite popular. On his videos that aren't weather reports, his voice is more subdued. It seems that MacDonald based his voice on field journalists who shout to be heard over outside noise, but he uses it even in his indoor reports,like this one.
LissySandwich of The Bowlingotter Show is naturally bubbly and boisterous. Her husband Bowlingotter is as well, to a somewhat lesser extent.
In Welcome to Night Vale, Hiram Mc Daniel's green head always shouts, even when complimenting the Old Faceless Old Woman in the live show 'The Debate'.
The SCP Foundation has SP-2337 ("Dr. Spanko"), a talking bird that, at its quietest, is slightly louder than an average human shoutnote 90 dB, to be precise. At it loudest, well: when enthusiastic, 10 minute of point blank exposure to its voice will disintegrate flesh.