I have always found Gnome's Nautilus ugly. Even when applying different themes, it never quite looks right. Most of it is due to awkward spacing and layouts.
I've tried to make up for this by adjusting the background colour, list spacing and side padding in my gtk theme. I have also altered the icons in the icon theme folder to make it look more modern and appealing. The icons are a mixture from various sources as well as my own.
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