Here are several listed at Nonags (all of which receive Nonags highest rating - six ducks):
Agnitum Outpost Firewall
"Description: Agnitum has released Outpost Firewall, a FREE, powerful personal firewall for Windows. Outpost Firewall gives peace of mind from any threats by cookies, banner ads, e-mail viruses, backdoors, spyware, crackers, adware, and virtually every other Internet danger. Unlike other personal firewalls, Outpost starts protecting against all kinds of internal and external attacks as soon as it's installed. This is the first firewall with an open architecture and support for plug-ins, so its capabilities can easily be extended by thousands of developers worldwide. Outpost protects your system from worm and virus attacks that arrive by e-mail. You can filter e-mails based upon their content, and Outpost will prevent dangerous attachments from executing. Outpost performs web filtering, allowing parents, educators, and businesses to exercise control over the content that is allowed to reach your computer. There is a privacy guard feature, as well as a plug-in that will block banner advertisements from your web pages. Users can get free updates to Outpost automatically, using the program's built-in update utility. With its open architecture and support for third-party plug-ins, Outpost's functionality can be expanded to detect and protect computers from new threats that may develop. Current plug-ins include modules that provide full privacy protection against all kinds of active elements in e-mail and on the web, blocking of banner advertisements and pop-up windows, protection of e-mail from dangerous attachments and worms, content filtering for parental control, and detection and protection from port scanning and intrusion. Inexperienced users will appreciate the ease of installation and ability to simply set Outpost's protection features."
http://www.agnitum.com/download/
Kerio Personal Firewall
"Description: Great personal firewall that won't slow your computor down. Automatic stealth mode renders the desktop invisible to potential intruders. MD5 signature verification protects the computer from Trojan horses spoofing as trusted programs. Free for personal use. Easy to use. Try it!"
http://www.kerio.com/products.html
Sygate Personal Firewall
"Description:FREE for personal use, Sygate Personal Firewall provides best of breed security in a user friendly interface, protecting your PC from hackers, trojans and DoS attacks. New features include full-ICS support, protocol driver level protection, enhanced logging, and more. Sygate Personal Firewall is the first FREE personal firewall to offer protection from malicious code intrusions, keeping the information on your PC safe and private. Sygate Personal Firewall is FREE for personal use and business users can purchase seat licenses starting at $39.95 for our Award-winning Sygate Personal Firewall PRO."
http://soho.sygate.com/
ZoneAlarm
"Description: ZoneAlarm is the award-winning PC firewall that keeps your personal data and privacy safe from Internet hackers and data thieves. Shield your system with our proven, award-winning personal firewall. Keep hackers at bay with protection against worms, Trojans, spyware, and 46 types of malicious email attachments.."
http://www.zonelabs.com/store/content/company/products/znalm/freeDownload.jsp
I hope this has been helpful to you.
Pastork