I've also got spybot & avg on my windows pc and no probs with viruses or malware/spyware.
Granted, it's got Vista so the system has enough problems functioning without any outside attacks...how I miss my little mac
Sure, you can't play games, but there's something to be said for knowing that the computer will do exactly what it's supposed to do every time...also something about being able to have just about every program open at once and the machine never coughing about it.