Are you more interested in monitoring and logging or blocking of inappropriate web sites?
Are you needing different levels of access to the Internet?
I am using the free version of Untangle http://www.untangle.com at a couple of locations
Another person on the forums is using a paid version
We've been happy with it. I'm using it for the web control to block inappropriate web sites.
I'm not using the reporting function, and I think reporting is better in the paid versions where users login to get to the Internet.
Dave