Is AVG same as Avira? If yes then they're the best http://www.free-av.de/en/index.html use them for 2 years. think it faster and better than nod or kaspersky or others
I thought AVG 7.5 was great. I hated 8.0. It never worked well with Firefox. I removed it and the Firefox problems went away. Now, I'm using threatfire by PC Tools.
they are all good aprt from norton ( slows the system down ) the same goes for the free version AVG Kaspersky is good - auto update etc
I have used NOD32 and AVG in the past but I don't really like the newer versions. I am currently testing ThreatFire from PC Tools... So far so good.