McAfee VirusScan Plus 2009 Edition with 3-User License for free after a $50 rebate. Note that it is not necessary to own the previous version of the software to qualify for the rebate. Here is a screenshot for your reference. This program shields PCs from viruses, spyware, and has a firewall to protect against network attacks. It also features McAfee SiteAdvisor that warns about risky web sites before users visit them. Most places have it for over $50.
Originally posted earlier, this is just a friendly reminder.