Linux

I've always liked Zypper (and if I remember correctly, DNF was also fine), purely because it feels sane in everything it does.

We love to make a religion out of them, but a package manager is ultimately just a secondary tool. It installs other tools, which are what you're actually interested in using.
So, I shouldn't need to learn a scramble of letters to achieve that. I shouldn't need to think about refreshing the repository listing. The less I need to worry about instructing the package manager, the better.

My desktop is Fedora and I have a file server running Debian. I was doing updates to the Debian box through ssh and it took me way to long to figure out why dnf wasn't working.

Over the summer Zypper got a huge speed upgrade after decades of being one of the slowest package managers, and while Hayden James did give Zypper "the best score" (not really, (except if you assume they all got 5 in ecosystem size) all of them got 17, except Pacman that got 16), it would've been nice of them to mention that as I'm sure lots of people probably still have this idea of Zypper being sluggish and taking forever.
In fact, seeing as how APT is limited on simultaneous downloads, I'd wager that Zypper is actually faster than APT now. Probably faster than Nala as well.

Interesting they gave apt a higher score for ecosystem than pacman. I feel like I have to add custom repos to Debian more often than I have to use the AUR on Arch

I have been using Nix for a year now, and I am not looking back.

All regular package managers have a problem: Sometimes a system won't work if a specific combination of packages is installed. To prevent this, package managers block those combinations. However, how does the package manager know which combination would break the system? It is tested beforehand, and a list of illegal combinations is maintained. However, this comes with a problem: How do you test every combination of packages? If a package manager tracks just 1000 packages, there are 2^1000 possible combinations to evaluate. This means that when a package manager becomes more popular, and more packages get added, relatively fewer combinations get tested, therefore increasing the chance someone breaks his system by installing a unique combination of packages, that wasn't evaluated and apparently breaks the system. In other words: Package managers have a flaw that causes your system to break if the package manager becomes too popular. The common solution is to create a new package manager from scratch that does exactly the same thing as the old one, but isn't popular yet, and therefore works. However, since it works, it becomes more popular, causing it to no longer work.

Nix is different. It is designed from the bottom up that every combination of packages is possible. It is impossible that one package breaks another. This creates some other advantages as well: there is no evaluation to see whether packages break other packages, allowing maintainers to add more packages to the repository. The result: even though it is not even close to the most used package manager, it is the one with the most packages in its repository.

Yes, there are problems. The biggest is that there is no easy mode yet. But that can be implemented later. For now I see Nix (or something similar like Guix) to be the future of package managers.

Pacman is the best for the simple fact that it's simple. APT, DNF etc get into the weeds with complex scripts trying to update databases and other nonsense that has caused apt/dpkg to obliterate systems for me too often (over like 10 years)

but pacman is about as close as possible to "unzip in place and go home" I've never had the actual pacman itself break a system. And the only broken update I've had is the stupid grub one which I solved by switching to systemdboot. On top of that even IF you somehow obliterated an arch system it's trivial to chroot in, use a statically built pacman, then reinstall all system packages with a single command.

I unironically use arch in critical production systems as i genuinely find it to be more reliable. Slap on some filesystem snapshots as a just in case for any bugs from updates (never had to use) and I have a system that is so much easier to use and i feel more confident doing updates

Even niche distros like Slackware, Gentoo,

Ooof - I'm feeling old when these are considered "niche" distros....

I prefer Flatpak

App images, love the fact that they exist thou sometimes graphically jarring. Sure.. ever only used them for two different applications. Both pretty niche. And not available in my distro repo or flathub. Not advocating for it to become something universal,or anything but they seem pretty distro agnostic. Which I'm guessing is easier to maintain? Or not? Not a developer.

I like pacman. Cachy here.