cloerr What do you recommend for desktop protection?
I depends on what you want to be able to do and use your desktop for, and what threat model you have, and what consequences you might suffer if the security fails.
For example Tails might be a very suitable choice for an activist that must be certain no traces of the usage of the computer remains after it is shut down, but the OS is very limiting in terms of what you can do.
On the other hand, Windows is probably more than adequate for most people, if used right.
cloerr What system do you prefer?
I use QubesOS, since I am in need for security domain isolation in my threat model, and QubesOS offers an easy-to-use and secure implementation of that.
QubesOS includes telemetry by default though, inherited from Fedora and Debian, so some custom configuration is needed for it to meet my privacy needs.
DeletedUser299 Tails, Kicksecue, Whonix or Qubes
These are all excellent choices for activists and journalists, but may be too limiting or inconvenient to use in other use-cases.
__Blank__ I have some difficulties to trust Ubuntu... Because they've done silly things in the past..
"Silly things"... They outright included spyware in their system. Yeah, I will never be able to trust them again either. I switched to Linux Mint when they did that, and back then Linux Mint didn't care about security and actively discouraged users from installing security updates, since it "might break the system". So yeah, that is how big the betrayal from Ubuntu was.
Ubuntu still regret their decision today. A lot of user fled, and never came back even after they removed the spyware again.
Linux Mint also improved their security posture to match Ubuntu's shortly after, to cater to the many security and privacy conscious users that fled Ubuntu. Though it is not obvious to me Linux Mint is a better choice than Ubuntu today, from a purely technical perspective. They are pretty much equivalent, being Debian derivatives with no further hardening applied.