I think everyone would like FREE AntiVirus and Firewall solutions, I know I would.. At the same time I also look at the resources needed to run these
programs since speed and memory is very crucial for me.. Kaspersky/AOL AVS is very good but uses up lots of resources to run in the background and scanning is slow.. If I were to go with a FREE solution for my needs, Id probably pick AVIRA AntiVir for its low overhead and good heuristics engine.. I use Eset NOD32 because its built in assembly making it a very quick and efficient but because its a paid for solution, it probably wont be on your list if your looking for a free alternative..

For free firewalls Id use Jetico v1 if your looking for a basic low resource firewall, Comodo Personal Firewall for a great UI but heavy resource and ZoneAlarm for an in between of the two..

A paid solution that Ive been trying is Outpost v4 which I find pretty good also and its not that resource hungry.. It includes a spyware filter/Ad filter/Content Filter which is a nice plus in a firewall..

The best way to decided is to test them for yourself.. Because program vendors are constantly updating their software, one program may end up being better than the other down the road..