Im with Becky Rose, If your smart, careful about the sites you visit and what you put into your machine, then theres really no need for a Virus scanner.
Well you're both wrong. A brand new Windows 2000 install was corrupted beyond repair after just 8 hours of doing absolutely nothing online. Accidently visiting a russian pr0n site, is one of the less evils you can do to your PC. Being ignorant about security is much more severe than all the Russian pr0n in the world.