Everyone is looking for a good free firewall.
Gratis Software Site tested a few free firewalls.
There conclusion is that the firewalls who are all ready a while on the market -ZoneAlarm , Sunbelt (previous Kerio)- loose it from the newcomers.
You can read the whole test on there site (dutch).
The winners of the test are: PC Tools Firewall Plus and Comodo Firewall Pro.