You’ll clearly get responses that are highly biased towards Framework here. Based on that, I’ll try to take a different approach.
System76, Tuxedo, and Starlabs have by far better Linux support than Framework. Their main selling point is great Linux support. System76 and Tuxedo even have their own distros, and all of them officially support multiple distros, not just Fedora and Ubuntu.
MNT is probably Linux only, but it’s awesome. For example, it allows you to replace each cell of the battery. As someone previously mentioned, it’s not quite ready to be a daily driver, though. Additionally, it features a mechanical keyboard and trackball, and the pocket version has an orthogonal keyboard.
Framework running Linux was a second thought. I’m glad that they now officially support Linux, and I think they are doing a great job in this regard.