I prefer 'ZoneAlarm PRO Firewall 2010'.I think that is the best one.I like that one because of some features of it like Two-way Firewall,Compatible with anti-virus software,Multi-layered security for your PC and so on..ZoneAlarm Firewall Pro is a great product that will keep your computer safe from intrusions and online Internet threats.

Firewalls should protect while not being too intrusive or too complicated to handle.

I also have same opinion about the ZoneAlarm. It has multi layer security mechanism that can secure the PC from the Internet viruses and spy. So basically all the security functions are available in one application.

As per my experience best firewall is Online Armor Personal Firewall. It is the bests all comers in the most rigorous testing, earning kudos for ease of use and low system drag. Through this firewall You can keep your private data to yourself with the personal firewall that stops hackers from breaking into your computer.