There's definitely some ugly bits from that era, but I miss...color.
My favorite example are the icons in the iTunes sidebar, which used to be distinctly colored (and therefore quickly and easily distinguishable!) and then became a dull grey. It looks incredibly bland and it's harder to use.
Now it's split into multiple apps with monochromatic sidebars, which is slightly less boring but no more usable.
I had some firsthand experience of how many people were bothered by the grey iTunes icon change after I released a little hack to restore them. The demand blew through a month of my web hosting bandwidth in a couple of hours, and people kept sending me emails about it for years! Comment from a previous discussion:
My favorite example are the icons in the iTunes sidebar, which used to be distinctly colored (and therefore quickly and easily distinguishable!) and then became a dull grey. It looks incredibly bland and it's harder to use.
Now it's split into multiple apps with monochromatic sidebars, which is slightly less boring but no more usable.