Connecting your laptop to the local coffee shop’s Wi-Fi without a good firewall and thinking you’re secure is like using a condom with thousands of holes in it and calling it safe sex. Your antivirus application is a good start, but if you want to make sure you’re computer is safe while you’re connected to the internet, a solid firewall is a must.

Comodo Firewall Pro (Freeware)

Comodo Firewall Pro is a powerful, free firewall utility. The application’s simple, clean interface belies its power, but make no mistake: Comodo is an excellent firewall packed with advanced options. In addition to the firewall, Comodo also comes packaged with an anti-malware tool called Defense+. If all you want is the firewall, be sure to select that option during installation.

ESET Smart Security (Shareware)

ESET Smart Security comes from the same company that makes NOD32. ESET Smart Security includes the NOD32 Antivirus along with a firewall and anti-spam filter. As a full-service solution, ESET Smart Security isn’t cheap at $60, but a 30-day trial is available. Like NOD32, Smart Security is a powerful tool with a small memory footprint.

ZoneAlarm Free Firewall (Freeware)

ZoneAlarm is a free software firewall from a company called Check Point. Not only does ZoneAlarm detect inbound intrusions, but it also lets you set per-application limits for outbound connections—meaning you can stop Google Chrome or iTunes from phoning home whenever they want, for example.

Your Router’s Built-In Firewall

Despite our request for a software firewall, many of you were still adamant about sticking with the firewall that’s built into the router you’re using on your home network. Fact is, if you don’t use your computer outside of your home, you don’t necessarily need a software firewall—and you don’t have to run a separate application eating up RAM to get great firewall protection. However, as soon as you and your laptop leave the safety of your home, your laptop has essentially no protection if you don’t set up some sort of software firewall. So while your router’s firewall may be great, just remember: It can’t follow you out the door.

Windows Firewall

Arguing that it gets a bad rap because it’s a Microsoft product, many of you are perfectly happy with the default Windows Firewall. It’s built directly into Windows, runs quietly in the background, and blocks suspicious attacks without requiring you to install any third-party software.