> I think the Royale theme was nicer than Luna
Out of all the 'official' themes, my favourite was the Zune theme. Grey/Black with sprinkles of Orange.
https://media.askvg.com/articles/images/Zune_Theme_XP.png
The default Zune wallpaper was bad though, so always changed that.
As for the icons, I liked them but they could look a bit unclear as to what they were supposed to represent. Windows ME's icons looked a bit clearer, but even those were styled a bit bizarrely to me: soft-rounded edges for icons that basically looked exactly liked the hard-edged Windows 95 icons.
What I think were better than XP's icons themselves were XP-inspired icons that came out at the same time, bringing a bit of polish to icons that were still using only 16 colours in a 16x16 resolution.