Perhaps it's better to switch the question around a little. Which desktops does Linux rule? Which desktops could Linux rule? Yeah, I know there should probably be a "dude" in there somewhere, but let's get back to the question. In its current incarnation, what kind of desktops are most appropriate for Linux, and what must be done to the free OS, and perhaps peoples' attitudes towards it, to expand its suitability to most, if not all desktops?