SteamOS is Valve’s Linux-based operating system. It features a seamless user experience optimized for gaming, while retaining access to the power and flexibility of a PC, and plays tens of thousands of games on Steam. SteamOS officially ships on Steam Deck, and will soon ship with certain Legion Go S models. We’re currently working on adding support for more devices.
Honestly, these are the ones that matter. From those, you can choose depending on what type of work are you planning to do with your computer.
For servers: Red Hat (but it’s paid), OpenSUSE, Debian, FreeBSD
Desktop (very new hardware): Arch, Fedora
Desktop (other hardware): Mint, Ubuntu, Debian
Hardcore, embedded, very specific needs: Gentoo, Slackware, Arch