Quick answer: there isn’t one.
The question is: What’s the best Linux distribution for your purposes. The answer will depend, partly, on how much effort you want to put in to installing Linux.
First a note on “distribution”. A “distribution” is, more or less, a kernel, a set of imoprtant libraries, a selection of important software, a window manager, and a desktop environment.
The kernel is the glue that holds all your hardware together. It’s a set of instructions (again, more or less) that tell things like the keyboard how to interact with the screen. And all manner of other hardware connections.
Important libraries and software are the things that get the machine doing things. I know that’s vague. But at this stage, unless you’re intending to dig into the real nuts and bolts of how the Linux operating system works, all you need to know is that it’s the cool stuff, like web browsers, word processors, media players and so on.
A window manager is a piece of software that defines what it’s like to be a window, and interacts with the kernel. There are two main players in Linux: Xorg and Wayland. The details are not essential to getting you up and running; soffice to say, Wayland is newer and tries to address some weaknesses and inefficiencies of Xorg. But either will work perfectly fine for garden variety day-to-day use.
The desktop environment includes things like sidebars, top bars, menus and the like. There are a lot of competing environments out there, but the ones you’ll likely run into are Gnome and KDE. They’ve always been the big players. (Currently, I use Gnome, so these articles will be rather Gnome-centric).
Now, for the purists among you (and this used to be me!) there’s Slackware. It’s the oldest still-maintained Linux distribution. But installation is not for the feint-hearted. If you’re just getting started, and just want to experience the Linux desktop, this is not for you. However, if you’re interested in learning Linux at a much deeper level, challenge yourself with Slackware.
If you want a lot of control over what will be installed, then Arch might be for you. Again, it helps to have some knowledge of what’s going on under the hood. So again, depending on your purposes….
Debian is an extremely stable distribution and is the foundation for several other popular distributions, most notably Ubuntu. Debian includes only truly free software, so any third-party software will be up to you to install. If you want Debian’s stability with all the bells and whistles already available, then Ubuntu is an excellent option. Similarly popular is Mint, which is based on Ubuntu.
“Based on”: anyone can create a Linux distribution, and one way to do so is to pick one that already exists, then modify it for some purpose. The makers of Ubuntu have decided to start with a very stable distribution and modify that. The makers of Mint … You see how this goes.
I’m at a point in my life where I just install a full-featured distro (short for “distribution”) and remove anything I don’t want. I was a dedicated Debian user for a long time, but with kids and other responsibilities, I simply don’t have the time to install third-party stuff in a pinch — especially now that the kids have their own devices! Ubuntu (and Mint for that matter) is easy to administer and their software repositories contain everything I want.
A note on “repositories”. These are libraries of software that the makers of the distribution have bundled up into “packages” and offer for download. Linux offers several ways to interact with these packages, both graphically and from a command line. Details will vary from distribution to distribution, so you’ll need to look into how the tools work in the distribution you choose. (Debian and Ubuntu use apt (Advanced Package Tool), which does a good job of keeping track of dependencies and resolving conflicts.)
Summary: If you want to install and go pretty quickly, then Ubuntu or Mint are good places to start. Check out some screen shots and reviews and see which one resonates with you. If you want to get into the nuts and bolts of things, look toward Arch or Slackware.