Typically, your default file manager on Linux depends on whichever desktop environment you’re using. If you’re using anything GNOME-based like Ubuntu, you get Nautilus. If you’re using anything KDE Plasma-based like Kubuntu, you’re looking at Dolphin. They’re all fine, but I wouldn’t call them “perfect.” For instance, Nautilus looks clean, minimal, and extremely polished, but lacks a lot of useful functions you’ll find in Dolphin, which, in turn, looks somewhat raw and unrefined.
