The build-in XP firewall or another simple but good packet filter like wipfw or CHX-I.
Within security, that's not exactly true. Offering no network services is better than offering network services and then adding a firewall to protect them.
Please be more specific about what you expect that software package to help you with.
Security products can only protect you against what they already know about.
Agreed. But competent and independent reviews seem hard to find.
You need inbound protection from a good packet filter. Then you need a good anti-malware product to help you try and stop malware at the gate. You don't need a big personal firewall piece of software to try and control malware already running from "phoning home".
Then you need to follow a few rules and use your common sense:
- Keep your software patched True for windows as well as for your other trusted app's.
- Don't run software you don't trust. Run only software and programs from vendors you trust, or from normally trustworthy download sites. Not from files received by e-mail, from a chat friend, from questionable web-sites, from file-sharing applications or from somebodys home-made CD etc.
- Use another browser than IE for your daily surfing and another client than Outlook or Outlook Express for your e-mails.
- Don't click links in e-mails or on questionable web-sites without checking that what it directs you to seems trustworthy.
And then it's a good idea to keep an image of your system in a known clean state together with regular backup's of your important data - so that when you have the slightest suspiscion about some kind of infection - revert to that clean state instead of running tons of different malware scanning/removal tools. Restoring from an image can be done both faster and more reliable than running removal tools.