AVG is free and will remain free and Comodo is the free firewall that I use.
Paying for this kind of stuff is stupid.
Is Comodo better than Zone Alarm?
I've done 1000 installs, reformats, etc, and Norton and McAfee are memory hogs, their antispyware scanner is known for MANY false positives because of the simple regex patterns it uses, and once I switch them to avast! it's like a new computer, evrything runs much faster after norton or mcafee is replaced, don't fall for the hype, bah, I've been over this before.
Between AVG and Avast, I would go with AVG. Although I did not appreciate the way they promoted v7.5. Like Tony, at first look I thought they were going to be all paid. I used to use Avast and it did a good job but I just find AVG a little better.