DavidR
10
Personally I use Outpost Pro it is a very good firewall but it isn’t the most user friendly if using it in Rules Wizard mode as you get asked a lot of questions for which you need some experience of your system and what is going on.
I used to and to a point still recommend ZA Free but they are changing how that is delivered with additional applications available on a trial basis (in the hope you my upgrade or buy, etc.), but it still has one of the most user friendly interfaces for novice firewall users. I don’t know what the issue was that turned you off to ZA but there are other options.
There are a few topics/polls in the General forum about firewalls, so a forum search for firewall should find these.
Zone Alarm free http://www.zonelabs.com works fine with avast and has a reasonably friendly user interface. There are others, Comodo, Sunbelt Kerio, Jetico, etc.
See some firewall tests for comparison, some are freeware but many are paid for versions http://www.firewallleaktester.com/tests.php. Also see http://www.thefreecountry.com/security/firewalls.shtml