Which one(s) and why?
Pop!_OS. I previously got stuck on tiling window managers, but I found that they have prohibitively large amounts of setup involved. It’s also not uncommon for support applications to be poorly maintained or to have a poor UX. Pop!_OS’s desktop gathers everything together very nicely into a working shell with minimal setup, but still has that sweet, sweet tiling WM.
This kind of setup works best for me, a desktop environment with a tiling window manager on the top, that way I can use it like a normal desktop for most things and can hop back and forth between apps I use a lot all on the home row with the window manager.
Not sure if it qualify as distrohopping, but for a long time I tried to test every major Linux distro release, and they all had problems with sound, but when Ubuntu 5 came out everything worked out of the box, so I switched my desktop to Linux. A couple of years later, Ubuntu began some introducing some (IMO) questionable things, so I tested the main distros again and landed on Debian, most of all because I knew the system relatively well from Ubuntu.
The first desktop distro I tried was Mandrake (back in 1998), but since I use my desktop for making music, it was just too much work every time I wanted to record something back then.
As for servers, I have always just used what the customer wanted or had, and for most parts it was Red hat.