I'm a big Pop!_OS fan. Based on Ubuntu so great for following guides and comparability. But no Snap, Flatpak is installed, the OS looks fantastic and runs smooth and gaming on it has been great.
+1 for Pop_OS. They also have a version with Nvidia driver support out of the box. Their UI is also a fantastic edited version of GNOME, so it's sleek and easy to use
I thought Ubuntu was the best distro to get started as a gamer but it required so much tinkering. Pop like mentioned had Nvidia installed and with flatpak integration it just made everything honestly fun again
Another happy pop user here! The business model for system76 is basically to make a distro that works seamlessly on the hardware they sell. Side benefit: their distro also works seamlessly on a bunch of other modern hardware, and they pay a lot of attention to quality of life features that make hardware customers happy.