Currently running Ubuntu 16.04, and Raspian on my RasPis. I have been pretty interested in ArchLinux lately, but I just like a desktop/workstation that "works" because I don't have the time or patience to fiddle with my computer after work since I have a software developer job.
Currently, I'm trying to learn how to use Kali Linux with all the security suites. Also pretty interested in Tails for similar reasons.
I used puppy quite a while ago, I didn't really like the package manager, but it was impressively lightweight. Are they still actively maintaining it? I was also under the impression it wasn't exactly set-up for Desktop but more for live-USB or live-CD.
I used to use Gnome Classic, LXDE and XFCE, but it's nice to know about new ones. I loathe the new Gnome and Unity.
MATE and Cinnamon are pretty good too.