Norton used to be top-of-the-line.
Not trying to start an argument, but in general, Norton passed its prime years ago.
Most would insist that Kaspersky is the current top dawg of anti-virus software, I don't have it, but I've heard mostly positive reviews about it (save for apparently it's a real RAM eater), and many computer repairmen and technicians I've alked to have recommended it.
Until I can try Kaspersky, unfortunately, I'm saddled with McAfee... it was great at first, but ironically (not really), when I paid for the service (it was originally complementary), it's slacked. It would be a good idea for people to probably download and install Malwarebytes' Anti-Malware and Spyboy's Search and Destroy; not only are they free, but they can detect the things that these once "top notch" programs can't. Matter of fact, if it wasn't for Spybot, I probably would've had to dish out a hundred dollars or so to have the repairmen remove those dA viruses that plagued me.