openSUSE (tumbleweed):
- rolling distro but actually stable ( unlike arch ;) )
- snapshots per default
- has one of, if not the most advanced sys management gui
- buildservice (similar to the aur)
- most feature rich installer
- almost all desktop environments are available ( KDE, Gnome, XFCE, sway, cinnamon, etc)
- best logo ^^
Not that popular but technologically one of the best!
Windows. More specially a netbook with vista, that ran so incredibly slow ot of the box that it pushed me to install linux. Technically i used Firefox before that, but that was when Firefox was the de facto standard in Germany, so i didn’t care about FOSS.