Those of you that are old enough to know what load, peek, poke, etc... stand for, used to have a "gaming PC", in other words, a Commodore 64/128, a PC made for programming, that was however mainly used for gaming by most users. Those have a really good time these days with open source games, because they can play games with full performance, that is, with systems that don't have to carry the burden of a desktop environment or a compositor, etc..., they will have no trouble running their games from CLI on their linux machines.
Those that ask themselves how to get R9 290x fps rates with an Intel iGPU, are not amongst those.
Those that think that everything that's not prepackaged, walled gardened, premium-priced and major brand-named, sucks, are not amongst those either.
Those that think that you need a 3000 USD gaming rig to get the best performance, obviously haven't been learning anything from using computers.
The best gaming distro, doesn't exist. Oh, we can point users towards Manjaro Openbox or SparkyLinux or Sabayon, but that's just a misguided attempt to show people an easy way out type of compromise.
The fastest way to start a game on a PC, is through the command line, on a system that isn't running a compositor, isn't running a bunch of PIM functions and communications/notifications TSR's, isn't running a bunch of software to provide compatibility with commercial software consoles and their retarded filesystems or communications protocols... and that with any linux distro of choice...
I'm sure that there will come a point in time where people will appreciate DRM-free games again, because no DRM means no GUI client necessary to run the games (e.g. the steam client), which means a lot more system resources free, which means a lot more gaming performance on any hardware.
I'm sure that there will come a point in time where developers will come up with the next-gen gaming experience, that will require so much resources, that the only way to run the game smoothly, is by dedicating all of the resources of the machine to the game. All popular desktop environments have been following the bad example of MacOS and later of MS-Windows, and have become ever heavier. I remember the pre-Windows 3.1 days, where MacOS was king. Most users had PC's with 640 KB of RAM, some even with 1 MB of RAM, yet Apple Macintosh owners had to shell out a couple of thousand dollars for 8 MB (that's Megabytes, yes, less than the size of a single jpeg or mp3, and it cost a couple of grant...) of RAM to make MacOS, with it's tiny GUI, work at about the same speed as applications were running on MS-DOS machines with 640 KB of RAM. In 1991, a fully equipped Apple MacIntosh that could do the same as a 1000 USD MS-DOS PC, cost the same as a Mercedes Model 190 cost back then, the predecessor of the later C Class. How times have changed right? Wrong, consumers have gotten even more stupid, that's all. The thing that costs most about PC gaming these days, is the operating system the games are running on. It doesn't only cost the license of the operating system, it also costs a lot of money on things that aren't technically necessary, but are artificially made necessary by the operating system and consumer freedom limiting software like DRM and spyware and malware built into the operating systems.
If you look at what's REALLY necessary to have a great gaming experience, a graphical desktop environment, spyware/malware and digital rights management, are not on that list, nor are 600 USD GPU cards or 1000 USD CPU's or 400 USD motherboards.
The general stupidity of the "IT entusiast consumers" has reached unprecedented heights. Like for instance most "PC gaming enthusiasts" are convinced they need at least 8 GB of RAM. That is is wrong. There isn't a game they're playing that can technically use more than 3.6 GB of RAM, and most games run just fine with less than 2 GB of RAM. They just can't distinguish the operating system (well, software console...) overhead from the application system requirements anymore...
With the time robbing chaotic clickfest software consoles like MS-Windows have become, it's actually a lot faster to just enter "xonotic" (or even shorter "xon<tab>") in a command line, than to click your way through a bunch of eye-cancer-grade GUI crap that nobody needs. That is how far it has derailed. CLI is actually very efficient, even more without GUI bogging the system down.
A normally configured MS-Windows system with a regularly configured web browser of choice, will require more system resources than most modern games. You're not paying for the extra hardware because the game needs it, but because your software console needs it to run all of the spyware, malware, and useless background processes.
By looking for "gaming distros" in linux, you're going in the same direction. I propose that the experienced linux users would refrain from recommending "gaming distros" at all, but would rather direct people to the command line, because it's bloody more efficient in all aspects.