Interesting

Krebs on Security
Renewal Buddy: Comparison Shopping for Anti-Virus Software
http://krebsonsecurity.com/2011/03/renewal-buddy-comparison-shopping-for-anti-virus-software/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+KrebsOnSecurity+(Krebs+on+Security)

Key comment

Many Windows users will no doubt be perfectly happy using a free anti-virus offering. I have a ridiculous number of computers in my office and around the house, and have free anti-virus on three of the six Windows-based systems. One is running Avast Free Antivirus, another Comodo Internet Security, and the other one has Microsoft Security Essentials. Out of those three, I vastly prefer Avast, which seems the speediest and least resource-intensive.