graeme_p - 8:10 am on Nov 16, 2012 (gmt 0)
I have been using Linux for more than a decade, between one and four machines at a time, with not one security issue, and until recently I never did ANY security configuration on desktops. Currently three machines in my household, and my father uses Linux as well (I switched him to Linux because its easier for me to support, especially from a distance).
Third party repositories are another massive advantage over the Windows/MacOS way. My plan now is to use the latest Ubuntu LTS (for a stable OS) with Get Deb (and especially PLay Deb) repos for the latest apps.