Here some reasons i have heard and that are common outside usa:
-"Macs are for stupid people that can0t use computers"
-i have heard this less since OS X was relesased
-"You can't find any software / any illegal software for Macs"
-hey: all major graphic apps such as photoshop and freehand ARE for macs!! besides - there are over 6000 apps that are for OS X or work there. i have found anything i ever imagined about and even more for macs. if you hear this excuse, show them versiontracker
-but true for viruses: for most viruses you can't find the mac equivalent..
-"the tech support.."
-Hey, if i have a prob with an app i use, i send an email to programmer! normally i get an answer how to solve it within minutes, hours or by the next day. This NEVER happened when using windows
-"99% use windows"
-not true. lets say macs are 1-5% depending where you are. most graphics are done in macs. web design etc are better in macs. and for more 'casual users' there are always more and more who go to linux .. and then maybe to mac
-"pcs are cheaper"
-true. but calcolate you use the computer for the next 3-4 years? do you want a cheap or a stable computer? do you want a huge GHz that you notice on your electirity bills or something that uses better its sources? etc etc etc.
i'll continue tomorrow if i remember some other rants-