Norton sorta depends on the version and the year. For instance, when I was running Norton I had the full NIS package. I was on a static cable modem IP, outside the company firewalls, and had information that wasn't mine to risk. When I got it, the stand alone anti-virus was also crap, but the business oriented security suite was top notch as long as you installed it right. It was a little temperamental about certain things. Two years later, NIS was also unusable crap and the standalone anti-virus was deleting system files...
Of course, after they started spending more money on tech support than software development, they probably cleaned themselves up again. The main benefit of having Norton was that it only did exact matches instead of loose algorithms to catch minor alterations to previously detected versions. Those can be rather inconvenient when your file that resembles a trojan is rather important.
Regardless, you really don't need one. Stop downloading porn off warez sites and warez off porn sites, opening attachments from getabiggerpenis@omgwhatatool.com, and clicking yes when a website asks if you want free viagra. The same lessons your parents gave you apply to the internet, stay out of the bad neighborhoods and don't take candy from strangers.
Two years clean as a whistle, a few annoying tracking cookies deleted at various times. I'd have a longer history of being virus free, but I downloaded a key generator off a warez site instead of calling my brother up to have him find the CD case I left at home. Needless to say it wasn't a key generator, no working removal tool either. It was one of those nice trojans that downloaded other trojans and pretended they're rabbits in heat. I got to spend a couple days tracking the components down and deleting them all, almost as entertaining as a good game.

Edi: Government sites are worse than warez. The bigger the target, the better the odds, and governments can't do anything right, so they have terrible security. Since the government consists of liars and thieves, you shouldn't trust them anyway. The US congress has one of highest rates of criminal activity in an organizational body in the country.