QUOTE
After all these years of using AVG Free, I've not come across any problems reported by other users. It detects and removes all the malwares I've encountered minus the spywares of course. That's some someone else's job.
It doesn't hog my system resources, it hasn't crash so far, it scans pretty fast, it has frequent database updates, i can perform manual database updates, i don't get pop-up ads, i can schedule auto-scans and auto-updates, it has real-time detection, easy to find functions(user friendly) and most importantly it's free!
Avira AntiVir users get in-their-face pop-up ads and is slow when it updates online. Bitdefender hogs system memory. Avast has the interface not everyone likes. I bet 7 out of 10 Kaspersky users in Malaysia depend on keygens and cracks.
Many disgruntled AVG Free users either do not perform frequent database updates, do not maximize AVG Free's scanning abilities or they do not practice safe computing.
Instead of complaining that AVG Free does not detect certain new variants of malwares, you should instead zip it and send them to virus@grisoft.com. Easy right? If only more people do that instead of complaining like a small kid. NO anti-viruses are perfect.
You can probably brag to me how good your anti-virus is, but I'll stick to my AVG Free. Case closed.
Of MOST AVG AV Users, I must admit that you elaborated LONGEST on your Good Experiences with AVG AV. I salute to your utmost diligence.
From what you said, I disagree with the part of AVIRA AntiVir having pop-ups. They are in fact, NOT Pop-Ups.

It is their notifier. Just have your Firewall Blocked against the Notifier Program, Then De-Schedule the Notifier in its System, THEN Disable a few services related to it (SC Command) THEN, Disable it in AVIRA's own Options Panel. Voile. No problems.
***THE METHOD ABOVE IS ONLY SUGGESTED TO USERS WHO
KNOW WHAT THEY ARE DOING. USE IT AT YOUR OWN RISK. I TAKE NO RESPONSIBILITY FOR ANY MISHAP CAUSED.***
Lastly, I still place my Vote on AntiVir, NOD32, Kaspersky and AVS. The First three has NEVER Failed me and my expectations.
Cheers!