PC Tools Firewall Plus (Free)
I haven't noticed anything lately about this firewall so I thought I'd mention it. The current version is 6.0.0.88 and it is proving to be an excellent firewall for me.
I had been running a slightly older version of Comodo (3.0 I think) and getting along fine but with the new Avast 5, Comodo was flagging the definition updates as files that needed to be checked. I didn't want the keep clearing these file lists and I knew that the newer versions of Comodo are just huge beasts. I wanted something simpler. So I looked into PC Tools Firewall Plus. http://www.pctools.com/firewall/
I am very glad I did. It is much easier to make sense of than Comodo, yet it can be made highly granular if you want it to be. It tests just as secure as Comodo for both firewall duties and intrusion (receiving a 100% score @ Matousec's site http://www.matousec.com/projects/pro...ge/results.php
So, if you are in the market for something more than just a simple 2-way firewall (like free ZoneAlarm), consider PC Tools. It's a winner in my book...