When taking into account only free antivirus, what is the best?
-The best i've used so far is Google Pack. I've tried many types of antivirus, but Googles is the best by far. It also has spyware tools, Best of all, it never expires. http://safe-google.com/pack
-AVG Free addition from GriSoft is the best that I have seen. You can also download limited trial versions of programs such as Trend-Micro. Hope this answered your question :)
Source: http://1firstinfo-antivirus.blogspot.com