I don't know if this is good news but I started doing this a while back and found so many sites that it was futile to keep them in one list. These days I tend to keep them in contextual notes or databases.
Also many of them fail to pass one or two annoyance tests, but I find that they're worth it anyway. For example they are not mobile friendly in some minor way, like the touch target for their menu is annoyingly small, or they are a little bit cluttered, or use more CPU than I'd like (specific mapping sites).
So it's not easy to fit a perfect list, but it's impressive to me just how deep the less-discovered, high quality web really is.
(Also I try to make my own obscure personal sites all the time as my contribution to this mess...)