Currently I run GNU Guix on my desktop, laptop, and servers. I like the dedication to software freedom and the way package management works. Before that I used Debian until 2019, Trisquel until 2014, and Ubuntu until around 2010. Debian and Trisquel are fine and I don’t have anything against them, I just like the Guix package manager more. I’ve used Xfce with all of these (and before then, GNOME 2). I set it up the way I like it and it never changes.
I typically run LineageOS on my mobile devices, without microG or any proprietary apps. As I’ve said before my preferred OS would be some variant of GNU/Linux, preferably Guix as well, but LineageOS works well enough.
I run OpenWRT on my router, and had a previous router than ran LibreCMC (a variant of OpenWRT using Linux-libre).
Windows games are made for Windows so I prefer to use Windows for them. I don’t particularly want to turn GNU/Linux into Windows, I think it deserves better than that.
The most obvious difference going from Debian stable to GNU Guix is that Guix is a rolling release distro, not stable (in the Debian sense) at all.
Package management is also very different as it’s fundamentally a source based distro, although sometimes the build servers can provide prebuilt packages if they’re available. Also, Guix has the concept of “profiles” which group sets of installed packages; typically, there is a system profile as well as a profile for each user, but users can also create their own separate profiles. This means that a user can install packages to their own profile without needing root permissions.
Profile updates are done in an atomic manner, such that changing the set of installed packages (installing, updating, or removing a package) actually creates a new generation of the profile, and it’s possible to roll back to a previous generation if something breaks. This is true of the system as well as the user profile(s), of course. A profile generation can also be exported as a manifest, which can then be imported to create a profile generation on another system, allowing package management to be done in a declarative manner.
Finally, Guix has a commitment to ship only free software, and uses linux-libre as its kernel. Debian has a clear separation between free and non-free components but does ship non-free software, including firmware blobs, and I believe as of recently the installer provides them by default. There are unofficial Guix channels (=repositories) that provide these things.