It’s somehow hard to find an icon set that pleases people… From everything that I’ve seen, I have to consider that the one I liked most was Humanities, and then Echo.
I’ve recently found Faenza from Tiheum which also provides some very nice GTK+ themes. Though this icon set is in development and lacks some icons, I have to say that this concept is the one that most pleases me from everything that I’ve seen in the last 12 years.
I’ve checked them out with a wide variety of GTK themes and they fit well in nearly all, including the old Clearlooks and the new redesigned one.
This iconset also includes nice mono icons for the status bar in dark and light versions (just like ubuntu-mono-* sets).
There is no more need to use Ubuntu branded themes on Fedora when something far nicer is available from what I believe to be an independent 3rd party.