I agree with ZA going downhill after 2.6, and I really do recommend Sygate Personal Firewall (the free one). It's actually easy to use without being dumbed down and treating you like a complete idiot the way ZA does, so I think you'll do just fine with Sygate. It has a main window (normally hidden but accessible from the system tray) that shows graphs for up/down transfers, which apps are running that access the network, and a few other stats. As for settings, there's the list of apps that Sygate maintains which can be allowed, blocked, or set to ask you everytime they are launched - much like ZA. However, you can set advanced properties for each app also, such as allowing/blocking TCP only, UDP only, a range of ports, etc. but you can just ignore that unless you do have to configure permissions for a particularly finicky application to get it to run OK. (Has not happened to me, but might if you have a physical setup involving a local network, routers, etc. - something that goes beyond a plain PC-to-modem-to-cable/DSL connection.)
Finally, there's the options dialog which is largely self-explanatory, and even in the one tab where you choose which particular protections you want to enable/disable, there isn't much to pick from. That's the only part that can be confusing at first, however, hovering over each option with the mouse cursor brings up excellent pop-up explanations of what each item does. Many of the options are greyed out and pre-set to enabled/disabled because they're reserved for the Pro version of Personal Firewall. Trust me on this, though, only hardcore networkers really need the Pro version - the free version is totally adequate to provide good all-around protection. I trust Sygate completely.
If you, or anyone else, decides to install Sygate Personal Firewall and you're running a 9x version of Windows, definitely add the following line to your AUTOEXEC.BAT:
DEL C:\PROGRA~1\SYGATE~1\*.LOG
(I have Sygate installed in C:\Program Files\Sygate Personal Firewall.)
What this does is: in case you experience a crash and the harddisk needs to be SCANDISK'd upon the next reboot, all Sygate log files will be deleted before Windows (and thus Sygate) starts up again, preventing any trouble because of corrupted log files. Sygate keeps these log files open and active at all times so they're not properly closed if Windows crashes.
And in case you wonder: using this DEL line *before* SCANDISK is run to fix the harddisk is not a problem either