These are my top ones:

Protesilaos: https://protesilaos.com/codelog.xml and https://protesilaos.com/commentary.xml

HN: https://hnrss.org/frontpage

Sacha Chua: https://sachachua.com/blog/feed/index.xml

David Revoy: https://www.davidrevoy.com/feed/rss

Davep: https://blog.davep.org/feeds/all.atom.xml

xkcd: https://xkcd.com/atom.xml

YouTube - Michelle Khare: https://www.youtube.com/feeds/videos.xml?channel_id=UCGGZ_PO...

YouTube - TmarTn2: https://www.youtube.com/feeds/videos.xml?channel_id=UC36MGPf...

TIL you can get RSS feeds for YouTube channels. Thanks for this!