Steam Deck

Like others have said, use fedora. But use the nobara flavour of fedora, as its built from the ground up for gaming and fixes a lot of tricky edge cases before mainline does.

is PopOS! still the popular choice for desktop gaming?

Pop!_OS was pretty good for two reasons:

• System76 sells devices installed with it. Thus, onboarding (potentially new) users is something they put significant efforts into. As a result, it was a pretty polished experience that offers some unique functionality like factory reset and
• Easiest install for proprietary Nvidia drivers on the market

But, the Linux landscape is always on the move. And while the engineers behind Pop!_OS have put their hearts and souls into COSMIC (a new Desktop Environment), the current available version of Pop!_OS has seen only relatively timid changes. Thus, it has become less competitive over time.

For example, over the past two years, distros have erupted that come with built-in Nvidia drivers (pre-installed).

So, Pop!_OS has gone slightly out of favor. But, if you liked what you had back then, then it's still perfectly reasonable to continue using it.

But..., if you're actually interested in the latest and greatest Linux for desktop gaming, then we'd have to mention the following:

• Bazzite; built-on technologies made possible through Fedora Atomic. This is one of the few distros that, based on its installer, come with built-in Nvidia drivers pre-installed. Rock-solid atomic system that comes with all the bells and whistles without sacrificing any general functionality nor high security standards. Offers decent documentation (please consider to read up on it) and has thought up great onboarding solutions. All-in-all, it's (probably) the most hands-off gaming experience on Linux.
• ChimeraOS; this is more of a couch-gaming/console experience. Unfortunately, only supports AMD. Definitely worth mentioning still.

Honorable mentions:

• Nobara; Glorious Eggroll's (will be abbreviated to GE) distro. GE is well known for providing all kinds of gaming related goodies. For example, a popular set of Proton releases/derivatives is Proton-GE and it's often recommended over the others. So, the community was very excited when GE announced (and shortly after) released its contribution to Linux distros for gaming; a Fedora-based distro called Nobara. It did a lot of good things and still does. However, as a former Nobara user, I have to say that updates for major releases are pretty hit or (mostly) miss. This is not GE's fault; it's the nature of the beast. Reproducible distros (like Bazzite) are able to circumvent these issues with help of incredible engineering that goes on in the background. But, this is not Nobara's stronghold. (And let's not even talk about the bus factor.) If you're fine with potentially reinstalling every once in a while, then, by all means proceed. But, if you'd rather not, then other options are better.
• Linux Mint (Edge ISO); this is just the goodness we've come to appreciate from Linux Mint but with a more up-to-date kernel. Kernel updates often come with improvements to performance. So, with this, you won't be missing out. Like Pop!_OS, it's based on Ubuntu. The only caveat with Mint is the fact that it's not enabled to game from the get-go. The required steps to get it all setup aren't very hard, but it's great to just have everything setup for gaming from the start.

If you want arch but you have live (/jk) you can just use endeavorOS. It is Arch but with an easy installer that even sets up yay, so afterwards you can just write „yay [desired pakage]“ to install stuff

You have to enable firewall for each service (each port on which your pc is reachable) and I recommend systemd-manager to have a easy overview on which deamons are running.

Ah, yea, if you want NVIDIA driver, you can use nvidia-inst and to switch back to nouveau, use nvidia-inst -n

I got tired of the Ubuntu crap, and was delighted to find that plain Debian stable is fantastic now.

Use Fedora: easy to install drivers, easy distro, most things set up, not too much much bloat

If you want something more gaming oriented but still very desktop capable use Nobara

If you want the console experience on pc use Chimera OS

Unless you have nvidia and/or really new hardware, pretty much any distros works fine for gaming - I very comfortably use mint. But if that is the case, you'll probably want something more up to date like arch. Idk enough about opensuse to make any assertions about it though, so use your best judgement.

Pop is great for gaming, especially for Nvidia cards.

Check out Nobara

https://nobaraproject.org/

I'm running OpenSUSE and am very pleased. I even put it on my Steam Deck.

Only gripe I have with OpenSUSE is that it has very conservative defaults, opting for security first. So you will have to add your user to all sorts of groups manually to get everything going.