I think that Norton is the best, sure it slows up your computer, but as soon as I uninstalled it, I got a virus, its great. Now I use Avast, SpywareBlaster and CCleaner. The other day I deleted nearly 2 gigs worth of rubbish with CCleaner, its a must have
I must stress to be careful with Search and Destroy, it completely B******* my computer, because it deletes some windows components, I had to format my hard drive and re-install windows, do be careful