While this is a hotly-contested subject, our pick for the best distro for Linux gaming is Pop!_OS. This Ubuntu-based distro has a lot of refinements and tweaks for everyday use, including for gaming. There are even separate ISOs for Nvidia- and AMD-based systems. Simply choose the one relevant to you and you're golden. I will say that the Nvidia-based one works pretty well given the potential headaches that can come with dealing with Nvidia's drivers on Linux.