A good bunch of those are actually used by many too. We really are spoiled for choice.
This plentifulness is just poison (favorite poison) for me, because I easily end up jumping around distros when I find interesting one. 
I thought that it ended with EOS, but it seems to have been a gateway drug… 
Luckily I work in shifts so it limits my habit some what. 
I hear ya, I was geeking about one offering a River-WM based desktop yesterday (Prism). I did boot into it’s live ISO twice, but i forebear from installing it (for now).
I am tempted to give Solus a try. Also OpenSuse has been on my current list also, because it is something I have never been able to try properly; eon’s ago I installed it to my first laptop, but only toyed it for a while and went to Windows.
Solus is pretty good, and I really like Tumbleweed as well.
I have been hearing good about Tumbleweed. Definitely going to give a try to it at some point. Also Slowroll sounds interesting.
@ shodanx Does anyone have this actual list ?
Here’s one site’s list updated as of yesterday for active distros.
List that can be filtered. Total = 478.
Spreadsheet hosted @ storage.to