AVG is slow as sin, I can't stand trying to play a game that uses a lot of memory and then have my friggin' Anti-Virus lagging too, that just kills the power of the game and my computer.
McAfee is like satan's own version of Anti-Virus, everytime I've had that anti-virus my computer crashes, viruses get through, and the registration fails and I have to keep trying to fix it.
Norton is good, but slows the PC down WAY too much, similar to AVG
The best one, in my honest opinion, is the one I posted before. It doesn't slow my PC down, good options, and keeps my PC safe. I can even turn on my IP masking software and surf the internet invisible, which is a handy plus.