Norton sux, they even create a virus to cure the virus to show u it's working. McAfee is similar but no creative shit. Panda used to be my fav for years but they have gotten so complex that they use WAY to much of your PC's resources to run their program, like many AV progs of today.
AVG is stil a good prog although there may be better out there but the resource drain is minimal and catch most of the viruses and malaware so use SPYBOT for bot infestation.
If you're gonna pay for a AV prog then ZERO is spot on pretty much,
Google the AV scenarios for a compilation of comparisons to make your own decision.
GLK
DED