Kane Pixels[0] is the most popular Backrooms creator by a wide margin[1], and the recipient of that A24 movie deal.
His Backrooms canon is completely separate from The Backrooms Wiki canon. It has none of the prescribed "levels", or any other of the Wiki's infinite proliferation of boring bullshit. It's purely descended from the original 4chan post[2]
From all the backrooms channels this one is my second if not most favorite: https://youtube.com/@lostinthehyperverse - there’s something nostalgic to it rather than action and it focuses less on an actual entity horror.
(Note that the channel contains pre-backrooms videos, you probably want to start with 1997 in the name.)
Endless wiki spam nonsense aside, I think the biggest contrast between Kane Pixels' stuff and most other Backrooms-derived content is that he leans hard into the weird cosmic horror aspect and surrounding interactions with the world (and black comedy absurdity/tragedy to go with it, like a government contractor proposal to retrofit the Backrooms as an infinite housing complex), rather than just 'spooky endless office with squiggly monsters'.
After Kane Pixel, I recommend Return to Render, whose humour excellently highlights the absurdist undercurrent in the foundations of the Backrooms' lore.
(Note that the channel contains pre-backrooms videos, you probably want to start with 1997 in the name.)