Crafted to fit lower level of hardware as base for appliance. Stability of work. Community of helpful users. Ease of configuration and wide scope of useful plugins.

lots of options and plugin apps, lots of guides online, runs on cheap-ish hardware

I love that it is an open source all in one solution to help keep your network safe. It handles routing, DHCP, DNS, intrusion detection, VPN, firewall, and so much more. I put my ISP's router and my wifi router in bridge mode and let my NetGate pfsense box handle all my traffic. I like how you can ssh into it or use the web GUI. The wizards on the GUI are easy to follow to set up how you want your network to be. The hardware is small and doesn't take up a lot of room. The VPN wizards are awesome. It even has a package that will export a profile you can install on your iPhone or Android that will connect you to your VPN.