ZoneAlarm Security Suite
By LenX onZonealarm is the best firewall software out there. It has various versions like only antivirus, only firewall, including antivirus and firewall, etc., The software, when incorporating both antivirus and firewall, with also, an antispam software, forms the best Internet security suite you can have. The suite is the only thing you might need to be sure of security when you surf the net.
The full version, called ZoneAlarm security suite, has these features: firewall, program control (where you can control almost anything about any program you run in your system), antivirus and antispyware module, email protection, Privacy module (with cookie control, ad blocking, mobile code control), identity protection (a very cool thing), IM security (for things like Yahoo messenger, AIM messenger etc.,), Parental control, and Alerts and logs.
I am using the software for nearly an year, and if you just update the modules periodically from the internet, you neednt worry about your PCs security at all, you can just about browse to any website out there, and be completely free of thoughts about your security.

Be careful with Zonealarm. It caused my computer to stop being able to make HTTP (FTP, Bittorrent, MSN all worked fine) connections about 15-30 minutes after startup.