https://protesilaos.com/modus-themes/ are nice, I use the light one

I mostly use https://github.com/n3mo/cyberpunk-theme.el now, zenburn for years before that.

misterioso --- https://pawelbx.github.io/emacs-theme-gallery/

custom, year 10

I'm a savage that uses the default light theme

Awesome list so far, thank you everyone

I use spacemacs and have the themes megapack and a couple of custom themes I made- a total of 241 themes. I randomly generate a number and use that theme that day. Yesterday’s theme was really good: doom-outrun-electric.

Random theme from a collection is a really cool idea.

Do you keep tabs on your favorites and prune the collection?

I don’t prune it, but if I notice something I like about a theme, I note it down and then when I update my custom themes (I have a dark and a light theme I work on/update), I implement what I liked.

Modus-vivendi theme, it's one of the built-in ones in Emacs 28 (not in 27 I believe).