KDE 4.x is probably the most configurable desktop available and it has a dual pane file manager called Krusader that can be installed alongside the traditional browser-like file manager.
OpenSUSE is considered by many to have the best implementation of KDE.
http://OpenSUSE.org
Agreed. I'm not a big Linux fan, but I have had the least amount of issues with the OpenSUSE distribution. KDE has its own "feel", taking aspects of OS X and Windows and putting them together in a fairly good manner. There is a learning curve, but again I've had the best luck with OpenSUSE.
