I have tried Online Armor, Private Firewall, Filseclab Firewall, Comodo, Sygate, Ashampoo Firewall, and Outpost I might have missed a few more...None of the Firewalls are that bad and most are better than the XP firewall or even Vista...Yet I find that some do stop or don't recognize certain services in the administrative tools, and they do block them, which then leads to alot of errors or things not working properly...Also If you have a state of the art firewall and you get pop ups in the learning mode that you don't understand or get discouraged from constant pop ups and than decide to let stuff in.....or if the firewall is too hard to configure or if you are a beginer to firewalls ...The best of the Best with the best ratings won't be of any use to you...
The choice for a good firewall depends on the user or your preferences ...and understanding for advanced users or beginners..I find that the PC Tools is a full Firewall with no upgrades to the paid version and it is very light and easy to understand, hassle free, also it does go very well with Avast on Windows Vista and XP..."There is some issues with the PC Tools firewall with Windows 7"....Which they are looking into but their support in my opinion is terrible, and you have to be approved by the administrator to get on the Forum to ask a question...Lots of people with questions but nobody with answers...I'm stil waiting to get to their forum.....I could care less for any of their other software and don't even want to go there...
So In Conclusion I guess that most of the Firewalls you have...Paid or free, you have to be comfortable with that firewall and your Machine has to accept that Firewall with no issues or stopped services....Just my opinion after so many firewalls that I have tried..And feel free to add if I did miss anything here...I would also suggest a "security suite" where your firewall comes along with your antivirus it makes things much easier on compatabillity
Just not the PC Tools Security Suite unless you want to download 1 gigabyte of PC TOOLS security
Cheers !!!and safe surfing!!!!