good_egg: no, Norton is consistently written about as being a pile or rubbish. At least, by those that know what they're talking about.
AVG and Avast are, by test results, both very good.
Kapersky is also meant to be very good. It isn't recommended as much since it costs money. But I do believe it is very good.
Panda also used to be very good, but when I was using it a few years ago, I did have some issues with it (installing a bit weirdly, forgetting it was registered...).
Regardless, nothing will protect the user from their own ignorance and stupidity -- the main reason for viruses spreading.