Hehe, Grinler and I seem to have split this off to its own topic at the same time.
My brother just emailed me to say that McAfee Virus + Firewall Protection (provided free if your isp is Comcast) is better than AVG.
You know what they say about opinions. Everyone has one of their own.
A lot of people hate McAfee and others love it. I've never used it so can't tell you how good it is. In general commercial antivirus programs have better detection rates and offer some other features like Scriptblocking, being able to schedule scans when you want, etc. They are, however, heavier on resources and Norton and McAfee are almost impossible to remove completely now if you ever want to try something else.
Personally, I don't care for security software installed thru ISP's as they generally don't give you the control of the program that you would have if it were a stand alone product.
AVG is lite on resources and even with a somewhat lower detection rate--altho it has been known to detect some malware that others don't--if you follow security best practices, like refusing to open suspicious email attachments, you will be just fine and you can get a free firewall from the resources list.http://www.bleepingcomputer.com/forums/t/841/best-practices-pc-worlds-avoid-viruses-scams/