Symantec, the company who is behind Norton, has a poor reputation for computer security. I would only install that on computers that are owned by enemies of mine... that or Avast lol. Symantec has ignored very critical backdoors/exploits in favour of the US intelligence agencies, which ended up leaving the door open for numerous potential attacks. I would never advise anyone to use software made by a company who blatantly leaves the door open for malicious users, especially after the exploits have been made public a number of times... AND including after many reports covered that SYmantec refused (or simply neglected) to patch it
Go with Bitdefender, Kaspersky, or ESET. Personally, I'd stick with the first two, but ESET does pass my higher personal standards with lab testing. Pair it up with MBAM, and you should be good for the most common attacks. Going much further would start giving you minimal returns in computer security.
If you want a little extra security, and aren't too adverse to running a customisable firewall, get Comodo's free firewall. Last I knew, it was still the best free firewall, and even competed with paid firewalls.