How little viruses are reported and how many are reported has little to do with its actual performance btw. The 'i haven't had a virus since i installed norton' argument just makes me smile, and you know this because it hasn't reported one?
Similarly, one that reports viruses all the time is most likely broken. If you check the content of the files they are nearly always clean.
As long as you use a scanner to check your emails and your browser cache, particularly if your a ludite and use IE (and then you need to check windows system folders carefully given IE's dll exploits). The likelihood of serious viruses is extremely low.
So which is actually best? The least intrusive, lowest spec ones... norton and the like are neither, so imo they are only worth using for people who don't use their pc much and are likely to double click anything with "funny" in the filename
.
AVG was a nice one ages ago, but its kind of dated. As far as pay software goes, bitdefender is a decent enough one. For free, there's a few and they mostly do the job better than anything, checking out clamwin now...
Using a antivirus firewall is paramount to treason, hell is like giving Dawn of the Dead to Uwe Boll to edit. If your not lucky enough to have a hardware solution (nforce have it on chip these days
and routers handle most stuff), then something small and firewall only is the way to go.