After an exhaustive and exhausting evaluation, here's the tested distros ranked:

1. Linux Mint: Winner. It's Ubuntu, but with adults coming in to fix/remove the dumb stuff (GNOME 3, snaps, etc).
2. Manjaro with Cinnamon, but as neat as Arch-based distros are, I'd rather have something that third party vendors have actually heard of. Also, other Manjaros? See desktop environment list below.
3. Xubuntu: Not bad, but while XFCE is fine to drop into as a tourist, it's too inflexible to be a daily driver
4. Ubuntu Cinnamon: The right idea, but no reason for this to exist when Mint exists
5. Debian: Yay freedom, boo drivers working
6. EndeavorOS: Also-ran #4584 that will be dead and forgotten before you finish reading this sentence. The post-install welcome window tells you all you need to know: a massive grid of buttons with every random function someone wanted added.
7. Ubuntu: The desktop environment designed by a head injury victim whose only prior experience was hearing an Android 1.0 interface half-described to them over a walkie-talkie. Choked with anti-features like snaps (open source client/closed source server, apps don't integrate right half the time, craps up your mount table with dozens of fake entries). Still has good bones for a real distro to fork from, but any dream of Ubuntu itself being usable by adults to achieve goals has long died.
8. Arch: No installer, no inbuilt GUI, and every operation is an inch-thick bomb defusal procedure. That said, decent if off-beat package manager, and it handles third party open source installs via its "AUR" better than other distros. A fine base for a real distro to start from, but then you just have something that no third party supports (see Manjaro).

Connected to the above, here are the correct opinions on desktop environments:

• Overall: Too damn many. Half these things should die so their developers can work on the survivors, because every damn one has toddler-level bugs that you can stumble into within 3 minutes of first boot.

1. Cinnamon: The best available. Mature codebase from GNOME (before GNOME got dumb), modern UI features (icon-based dock, thumbnail previews, reasonable start menu).
2. XFCE: Not bad, but while it's fine to drop into as a tourist, it's too inflexible to be a daily driver.
3. KDE: I am shocked how slow it can make a modern computer, and how quick you'll find dumb bugs. Can't even do taskbar window thumbnails out of box.
4. Mate: Not broken, but also frozen in 2005. Welcome to Windows XP.
5. Budgie: Trying to the same as Cinnamon, but from scratch and at pre-alpha quality.
6. i3: Insufferable nerd shit by people that never learned what UI discoverability is. The vim of desktops.
7. GNOME: See "Ubuntu" above – this UI needs to be put out of its misery. I would rather learn i3 than put up with this shit.
8. Enlightenment: This is it, the most jibbering batshit insane environment tested. On first boot, a sequence of incredibly neurotic warnings pop up for things ranging from ACPI stepping revision of your motherboard to the notification that ethernet, in fact, still exists. The launcher icons violently explode continuously at you if you so much as hover over them. Right click menu includes an option ominously labeled "Run everything". I mentioned using it to a friend, and he replied "Oh, you don't know about the Enlightenment guy? He's nuts" and linked me this article, which states, among many things, that every interaction is based on the casting of void* pointers. I never thought I could look at a GUI and feel the pointer casting, but here, you can.