Human Interface Guidelines (HIG) are available for all the major desktop environments. OK- I’m guessing on Windows (I was right). But Mac OS X, GNOME, and KDE all have guidelines meant to steer developers to develop in a way that makes apps consistent in various ways.
For productivity, consistency can be key. Users need to be able to use their computers. Not groan every time they launch a needed, but bizarrely put together, app.
Apple for several of its own apps, tends to ignore their own HIG, choosing instead to make an interesting user experience. Since the launch of the iPhone, that thinking has blossomed- leading to UIs like these from Landing Pad.
At what point does a beautiful app distract too much from what the user is trying to accomplish? Is the HIG you’re developing for hold you back?