Your network-connected computer needs security. That's a blanket statement with no qualifications. In the corporate world, you rely on your IS department to make sure that your system and network are secure. At home, you probably run an antivirus program of some sort to protect you from the latest virus attacks on your system. And you've likely been thinking about adding some sort of network firewall, especially if you've recently gone to a broadband connection or any type of always-on Internet connection.
Quite a few personal firewalls are on the market. Small office/home office (SOHO) and home users often seem a bit scared of the whole deal. They worry about configuring their firewalls properly and wonder whether the firewalls will properly support their Internet connections. Even knowledgeable power users and IT professionals often find themselves bogged down in the minutia that can accompany the configuration of enterprise-class firewalls. And IT folks and power users who support family and friends understand too well that people who can't remember to update their computers' antivirus profile files are unlikely to want to learn about firewalls and related technologies.
I wish I knew how to protect those users who want to remain ignorant about what their computers are doing, but there's really no way to do that short of locking down their systems completely. You know you'll get calls for help from those people you recommend products to, so you'll want to recommend products that will result in the least number of phone calls.
For antivirus software, you should recommend a product that you're comfortable with and that automatically updates its virus description files. Automatic updates can help prevent panicked phone calls from users who get hit by a virus that an updated description file would have caught.
Firewall software choices are more complicated. Personal firewall products range in complexity from those that require minimal user input to those that appeal to users who enjoy recompiling their Linux kernel on a daily basis. Many free-for-personal-use firewalls fall between these boundaries, so you need to investigate which ones you want to recommend or use yourself. If you're considering a firewall solution for business users, either as a personal firewall within the corporate network or a package installed on all casually connected users' notebooks, make sure that you consider the upgrade paths and corporate support costs.