When evaluating types of firewalls for your organization, what's the most important functionality?

More important things in the firewall is

1- Policy used where the more advanced and powerful the better

2. AntiViures used in the Scan process                                  

3- its ability to prevent the breach before it happens

4. recording the events and alerts How is presented to the Administration of the network

and there are other things primarily do not have room to mention

first what the organization needs, and if the Firewall support it, for example does it have VPN or does it perform application layer inspection.

on the second hand what its the Firewall vendor because its a long term investment and the better the firewall the less maintenence it needs.finally the cost, the least cost is not always better, it depends on the previous points and what can the Firewall provide for future usess.