I have Norton, just the basic AV package. After a year of Firewall I realized that the two or three simple downloads from the net were doing almost exactly the same job but far more easily. No matter what I did, the very things I set the firewall to exclude, it ignored. I still needed spybot, hijackthis, a-squared.
I took it off a month ago, and have seen no increase in activity as to spyware, adware, viruses.
It was unwieldy, expensive, and I've noticed that not one site I visit recommends the Norton firewall for users. they suggest Zone Alarm first. that tells me a lot, right there.
Our biggest security risk is our own activity online, the way we use the net. Where we surf, as well as what kind of guards we have aginst the junk. Without that, if you get a virus, yeah, blame the companies for 'giving it to you'', but remember that some of these things, viruses and adware as well, are amazingly clever, persistent, and sometimes impossible to remove.
I see people who visit porn sites, animated graphics sites, game rooms, constantly. They are forever bringing back stuff, and blame the virus companies for it.
Frankly, no matter how good your protection is, if you persist in going to places that are known for this stuff, then you are sooner or later gonna find yourself face to face with some nasty surprises. Some of them even good AV softwawe can't handle.
and you can't expect a single program to do all the hard work. Even the best AV software in the world can be defeated by a virus that manages to circumvent it. And you need to know how to take charge of your own computer, not just let the AV do it.