What is the best free antivirus?

The best free antivirus is Avira, why? Because it gives a total protection and minimizing damage to Windows.

My second choice is Avast, it is as well excelent antivirus. The only weakness is : if it finds virus in a drive, it will damage the drive itself. What kind of damage? If you double click the drive, instead of opening the drive, you will be primpted by open with.

Last choice is AVG free edition. It is famous because it is the only antivirus that can remove Brontox Virus...
The only weakness is, it gives you a Heuristic warning all tje time when it fails to remove a virus..