NOD32 (paid) or Microsoft Security Essentials (free) would be better.
Somewhat surprisingly, Symantec had top-score in
AV Comparitive's 2009 tests, with Kaspersky taking silver and ESET Nod32 taking bronze. Of the free options tested, AVG bested Avira.
AV Test (published via PC World) gave
top position to G-Data, with Symantec at #2 and Kaspersky at #3. They placed Avira top of the
list of free apps, followed by Avast!, then AVG.
As for me, the last virus I had predated Win 3.11, so I can't remember what it was. I had to deal with Michelangelo on a friend's computer, which was probably the worst. Since then, I've had to deal with worms and other malware on others' computers, but few true viruses and nothing particularly nasty. Wait, I almost forgot about MS Blaster; had to deal with that when it first hit. Mine have been clean, but considering the number of viruses infecting BSD and OS X that are in the wild, this isn't much of an accomplishment.
Malware ads. Do these companies really think that this kind of crap gets their product sold?
Sadly, it does work on the technologically illiterate, who are the malware creators' real targets. Rather like how spam hits far more than its audience, an affect not unlike shooting flies with buckshot.