For me it’s MATE.
For some reason I’ve never really gotten on with XFCE. Tried it in earnest many years ago, and have dipped into it a few more times over the years, and for whatever reason it just doesn’t gel with me. Always feels like I’m fighting it to get it to do what I want it to do.
MATE has the familiarity and comfort for anyone who spent serious years running GNOME 2. It’s pretty much as lightweight as XFCE these days, but feels more polished and intuitive for it.
Ubuntu MATE is still one of my go-to distros for limited hardware (even though that project specifically seems to have stagnated somewhat in recent years).
Every single time. I know how I’m supposed to read it, I know what it means and where it comes from, but I physically cannot read it any other way.
Worst name ever.