Kagi nowadays has a feature called "SlopStop" that you can opt into. It's basically a global block list for LLM generated websites, etc that is shared across all users who opt into and anyone can report sites/content to it.
Kagi of course reviews it but generally it's good enough that I don't see much LLM generated content in the results anymore.
I was extremely pleased to login to my Kagi account and see that SlopStop was enabled by default. Thanks for the heads-up on this, and thanks to Kagi of course for enabling it.
They had quite some lag at the beginning. I made reports from the very day they announced it, and none of them were processed last month. But they are now! (Though they rejected half of them)
I had the same experience. I don't know why they haven't invested more in this feature. Heck, if they classified every site in their index as "AI/not AI" using machine learning, and had a large allowlist of "known-good" sites, that would take care of most of the problem (I am aware of the drawbacks of text-only AI classification, but they could use other indicators, like the site's publication date, domain name, domain registry date, etc.). I think for right now, the "state-of-the-art" for non-AI search is going to entail maintaining large whitelists/blacklists of websites that are crowd-sources by users (e.g. what you can find in some GitHub repositories). I was hoping that's what SlopStop was going to be, but it is not nearly as effective as it needs to be.
They started marking a lot of my reports as not slop when it’s very obviously ai garbage. Stopslop is nice in theory if they actually handle reports correctly. It’s exhausting to spend time trying to help clean up their results only to be told no.
I doubt that my list would be of much use to you, since a lot of the sites relate to specific hobbies.
However, as eloisius mentioned, you can view the most commonly blocked sites. Going through that list is a good start: https://kagi.com/stats?stat=insights
Kagi of course reviews it but generally it's good enough that I don't see much LLM generated content in the results anymore.