that you invest in a really good anti-virus firewall
( Zone Alarm, MacAfee or similar product )

Who has what type of that protective software, and what do you like about it?

I have Zone Alarm by Zone Labs.
I give it 2 thumbs up:
Firewall
Program Control
Anit-Virus, Anti-Spyware
E-mail protection
Cache cleaner
Identity Protection
IM Security
Parental Control
Alerts & Logs
Automatic updates


( from someone who had his last computer decimated by spyware ).