Yup, I still think the AmigaOS 1.3 was the best looking OS ever (eat your heart out MacOSX)... we seem to be quite alone on this issue though.
Hmm, now that you mention it... I bet an Aqua-ish (MacOS X candy/glass) GUI with gadget/winborder design and colour scheme copied from AOS 1.3 wouldn't totally suck!
OS1.3, and Just add water! (TM)