Which free antivirus softwares are better and why?

Avast, Antivir or AVG? I heard AVG is bad in updates and virus database.

Which free antivirus softwares are better and why?triumph

I prefer Avast because when i detect virus on a executable program Avast ask if you want to delete or move, AVG delete a executable program without ask, when i have the virus Win32 AVG see all executable as a risk and delete them,In Avast i remove this virus without delete a executable programs(except the infected programs).

Which free antivirus softwares are better and why?worms

AVG because it works
Here is a list of all the major free anti-virus programs:

Avast:

http://www.avast.com/eng/avast_4_home.ht...

Anti-Vir:

http://www.free-av.com/

AOL AntiVirusShield:

http://www.activevirusshield.com/antivir...

AVG:

http://free.grisoft.com/doc/avg-anti-vir...

BitDefender 8: (on-demand only, no real-time protection)

http://www.bitdefender.com/PRODUCT-14-en...

Clamwin: (on-demand only, no real-time protection)

http://www.clamwin.com/

I have tried them all and personally I like the new

AOL AntiVirusShield the best. Don't let the name AOL scare you. AntiVirusShield is made by Kaspersky which in test after test is always at the top or very near it in virus detection rates. Plus it is very lite in resource use, only about 5 MB of RAM. While not having as many features as the $40 Kaspersky program, it is 100% free to anyone, AOL member of not.