Kerio and Sygate are both definitely, from personal experience, better than Zone Alarm, so that cancels ZA out. As for which is the better of the two out of Kerio and Sygate, well, Sygate and Kerio are both brilliant firewalls but I would have to say that Kerio offers way more in the sense of configuring, information and settings. Although Sygate is just as good but not as hard to get used to. Right now I favour Sygate over Kerio.