Why switch to linux? I want to spend hours compiling any programs i want to run, updating tons and tons of config files, I want to spend hours tracking down and compiling drivers for my system. Not to mention most users don't like working at a console / prompt. Linux is not an anwser unless a user is very, very tech savvy. IE System Administrators, or you have time to do alot of learning, not to meniton you dont like games
Mac? While it is a very cool OS, even their cheepst computers are more expensive than most people want to spend on a new pc, i can run windows on this im happy.
windows is easy to use and work with on a daily baisis, and by default it is fairly well locked down believe it or not.
The only way to get spyware, is to do stupid things on the internet, browsing sites you do not trust, installing programs they "like" but dont relize what they do, using P2P sharing programs like kazaa, shearaza, etc. The users who are having all the problems with spyware are the ones who are putting it on their own pc by installing programs like weatherbug and password managers and tool bars. There are a few very malitious spyware programs that will install themselfs, but most require a user do somthing to run it.
Spyware would not be a problem if everyone was smart enough to run linux