I ran Norton on my old Gateway until it let a worm,trojan, whatever through and crashed the hard drive. I tried CA and it basically brought the computer to a halt, so I switched to Kaspersky.
The Dell I got a couple of years ago came with McAfee and when the subscription ran out I went with Kaspersky as I couldn't justify McAfee's much higher cost and lower ratings.
On a side note, when I uninstalled Norton on the Gateway it took about 4 hours to clean out the registry editor. Norton doesn't like to be uninstalled and their customer service, some clown in India, Pakistan, wherever, is worthless.