I use Debian with GNOME.
I really liked Xfce the most. It runs so damn fast and seems more or less fully featured to me. It has some rough edges but these can be overcome with some patience and research, which is not always something people want to do. Their developers are a smaller team which less output but they have a healthier attitude towards feedback. I really like this one.
I've also been looking into perhaps using Devuan or FreeBSD. I think I will fire up a virtual machine and test these.
I don't really like KDE for some reason. It looks like a good project. I also havent really been swayed to try GNOME2 derivatives like Cinnamon, MATE, etc. Not sure why but when I want a traditiona non-gnome desktop I always fallback to xfce.