Free anti virus software?

What's the best one?

AntiVir
Avast

...are the 2 I know about - are there any more and which would you recommend?

AVG = http://free.avg.com/

Avast = http://www.avast.com/eng/download-avast-home.html

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


I've used these and prefer Avira but they are all good and free.

edit: Avira is AntiVir

have AVG, works fine for me.