|Anti-Virus

I was reading about free anti-virus software packages tonight. These were the most helpful:

• http://www.makeuseof.com/tag/ten-best-antivirus-programs/
• http://www.av-comparatives.org/
• http://www.techsupportalert.com/best-free-anti-virus-software.htm

What do you recommend--online info sources and actual software?