What is the best Gnome2 fork these days? I remember using Mate back when I couldn't stand Gnome3 - is it still the best alternative?
Cinnamon is actually a GNOME 3 fork created to turn it back into a more traditional desktop environment.
XFCE is not a fork of any version of GNOME, although it does have a UI similar to GNOME 2 and is based on GTK.
Personally, I switched to XFCE back when GNOME 3 came out, and have been happy with it.