LimeWire12
You ask your question as if it was ever so easy to answer, also I don't understand your comment about ZoneAlarm.
Your best bet, rather than asking the naive question "Which is the best firewall?", you need to read the various reviews of people/organisations that have tested these applications and weigh up the pros and cons of each product.
I would advise you to read through the
Home PC Firewall Guide website before choosing a firewall:
http://www.firewallguide.com/index.html
Then, once you have installed and configured your chosen firewall, test how well your PC is protected by going to
GRC's Shields Up website:
http://www.grc.com/x/ne.dll?rh1dkyd2
I personally use NPF 2005, although it is not a free product, I find it does its appointed tasks very well. I know, for example, that some people find Norton's pop-up warning messages very annoying and don't really understand them. But I take time to try to understand the warnings and whether they are real or a configuration error (security set too high).
And that is the essense of any good firewall, the ability to configure it to let in some internet communication without letting in the bad stuff and asking you if it not sure.
UK Bob