I currently use AVG but recently discovered BitDefender has a free version. I have heard so much about how great BD is that I started to wonder if I should switch. What do you think?
Bitdefender only has on demand scanning so no real time protection. Antivir is the best I've tried yet and free. http://www.free-av.com/
I'm with maca on this one... IMO, I've found AntiVir's real-time scanner is better than AVG's...just my two cents...