SelectingADistribution notes that a number of LinuxDistributions that exist only as "desktop Linux" do nothing but try to be Windows. As soon as you get past this mentality and realise that you are not locked down into simply trying to ape Windows, you'll get much further with Linux. That's what makes MacOSX so successful, too. Important differences between Linux and Windows:
You (can) know precisely what your computer is doing at every point.