Free, very quick, easy to use and rock solid.
I've used SME server as gateway for at least 10 years. I decided to give Untangle a try. It slowed my internet way down to the point common pages would timeout. I tweaked the settings for days to no avail. How this product gets a 5 star rating I'll never know. It is SLOW, but it sure is pretty.
Highly recommended for small business!
I was able to setup a gateway for my house in literly 30 min (after download) The interface is amaing, and the dyndns, automatic ip dns entrys, and the adblocker tops it off, to make this a great solution for a home or buisness