KDE for Windows
KDE 4.1 is here, and windows.kde.org packed it for Win32 already. As long as there are lots of useful apps in KDE without good win32 alternatives - I installed it on my working XP machine.
While Amarok is still in deep alpha - I couldn't start it. But there are two apps I can't live without - KWrite and Kompare. Both of them have great user interface, and gives you all advanced possibilities you can imagine. There is no other free editor to support about 90 different source file types and full encoding support, with possibility to open file with one encoding and to save with any other. There is no good file comparition program with such pretty and usable interface as Kompare. If you are interested - give it a try!
I am still waiting for Krusader and Okular, but my life under windows is already much simpler.