KDE. It's pretty good these days. I used it in 1999 when it was new. I used it in 2009 when it was messy. I didn't use it for about a decade, opting instead for tiling window managers and plain cwm(1) on OpenBSD.
I finally installed it again in 2021 and it's been fine. Solid desktop, does what I need it to, but requires a lot of configuration up front to not be annoying. I want simple and consistent, with double click to open things and single click to highlight, and I don't want a popup dialog box in the corner every time my Konsole bell rings. I want animations and transparency, but I don't want to wait a half a second for my window to minimize. I don't want workspaces, just like I didn't want a cashew in the corner of my screen 15 years ago. If I tell my dock to be floating, it needs to stay floating and not change its shape and size when I maximize my window.
KDE requires some tweaking out of the box so that it stays out of the way. But once set up, it's nice.
3.5.10 was the best KDE ever, but I'm on 5.27 and I don't have any complaints.