Well, I find it a little odd to buy extra protection from whoever your Os is from originally (hello? if you can fix the problems, why not do so in the first place?
) but third party tools are a-okay with me.
Norton specifically throws in a lot of different functions - some of them well known, others are relatively new like their online protection for ecommerece transaction. I am not even sure if they are the same used in other products. And then there is the really innovative stuff, too. They offer you something called online-updates where you keep your own files on their servers. (I assume there will be size restrictions, but I haven't looked yet. Anyways, that way even if your computer fries and takes the house with it - you still have your data.)