If I had to pick, Ubuntu.
What I'd actually pick: Fedora
Workstation Edition (Gnome) or Plasma Edition (KDE Plasma), whatever your UX preference, with Gnome being more polished, minimalist, distraction-free, and Plasma being like Windows out of the box but much more powerful and customisable.
The name unfortunately conjures images of the tips fedora/m'lady meme, but the name predates that, and it's a solid and well-supported distro that gets better with every update.
I don't really dislike Ubuntu; they certainly get a lot right. But they have also made a few choices that I'm not really into. Most of all, the direction of Ubuntu is somewhat unpredictable, because Canonical is a for-profit business that has changing priorities.