It's been quite some years since I tested it the last time, but SUSE Linux, which now is openSUSE (Yeah - "
now" - I know it's been
some years.

) came with some choices you may pick one, or install several, and then chose one from a list at the start for your X session.
What I did for my evaluation (many years ago) was,
I searched for and looked at some screenshots first to sort out the ones I don't want (which, looking back, was wrong; see next paragraph) then I installed a few I wanted to take a closer look at. On FreeBSD. You can install them all, and deinstall them afterwards, again. This ain't no Windows where there is a registry you mess up. There may some dependencies left, but those don't cause real trouble. If you don't want that anyway (I also prefer a clean machine with no useless garbage anywhere, not matter how small), either do a test installation, on an extra machine, an extra drive, or in a VM, which do not contain stuff of any value, you wipe clean afterwards, and install and check them out there.
However,
to decide if a DE/WM is your choice, you have to use and examine it for a while. Just taking a quick glance at it ain't enough.
In the first place I refused to use simples WMs, because they look so "boring simple old-school." But that's exactly where I finally end up. I am using now for several years: fvwm
2, one of the oldest.


(I explained why 2 and not 3 also two times here in the forums. If you must know, look for it. I'm not going to repeat it here a third time.)
Point is: I simply figured out about myself I have very strong ideas of how my desktop GUI have to look, what it shall can do, above all what it must not do or have, what I'm able to configure etc.
And I found out with neither DE I can be fully satisfied, ever, because those can only be configured within limits. When I want to configure everything, I cannot do this within their config menus, but I have to edit config files, which with many are not just one, but several, named cryptical, written in XML, ... they are not meant to be edited by the user.
That's when I realized: "Why not design your own 'DE'?"
Which brought me finally to WMs, which I can configure pretty simple they way I want them to be exactly, because with most(all?) WMs you can configure
everything, not only the menus, starting with the fact you don't need to throw overboard all the things you don't need/want, because there aren't any (or just very few as an example/template), but you only add what you want.
I even changed the window's title bar's buttons on mine.
See a picture of that in
my post.
Looking back It had been quicker, easier, and less effort if I had chosen this way directly in the first place.