pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
Cisco ASA - Cisco ASA Software delivers enterprise-class security capabilities for the ASA security family in a variety of form factors.
Palo Alto Networks WildFire - Firewall and Threat Intelligence
Qualys - Qualys helps your business automate the full spectrum of auditing, compliance and protection of your IT systems and web applications.
IPFire - IPFire is a server distribution with intended to use as a firewall.
Meraki MX Firewalls - Cloud managed networking from Cisco Meraki. The easiest and most IT-friendly solution for enterprise networking needs.