Plasma. It’s the most customizable and you can dive in and shape it. It feels much more natural for me to jump into.
I put xfce on older hardware.
Distro wise I tend to go with Ubuntu flavors most because they seem to have better compatibility for various software and stuff I need, but I haven’t really shopped around too hard in years. Work is RHEL (and clones) and they make me sad.
Snaps just act strange. They update in weird ways, it’s always automatic and it’s confusing how to keep something in a version that won’t auto update. It’s been a bad experience for me.