I have to say KDE Plasma, but I look really forward toward Cosmic Rust.
KDE is simply so damn old and has weird quirks everywhere, it has features and basic things like
functional apps: dolphin, spectacle, kate, kde connect, systemsettings, discover, ...
SSD with hitboxes in the very corner (looking at you GNOME)
wayland support
a regular but modular bottom panel
extensible everywhere
But it also just has too many features. Extensions are not tested or versioned so many simply dont work anymore, often some of the dozens of components has an issue. I cant imagine Cosmic reaching the level of features in like 3 years, but if it would do, this could be great. But in the end its up to the devs, so I have no idea at all.
I dont find GNOME usable really. At least in the default settings. The decorations make no sense on Desktops (they are perfect for tablets), the top bar makes you look down too much, the ubuntu way wastes space too. Everything is too thick, too little GUI settings and the standard apps could be from Android, the little features they have.