ClearOS (I used the earlier ClarkConnect 3.x and 4.x) was ok but a bit more than I needed (web shares and pages were more than I
needed).
I've added most of what I need on top of IPCOP. Filtering, time based controls are available.
I put in my own dhcp and dns to allow me to redirect the gateway to a non-existant IP so I can have a time period when my kid can use the network based printer and computer for homework -- but not get to the outside world to screw around with Social Networking or games... I ssh in and run a script to restart dhcp to allow access to the outside when the work's done.
Having openvpn so I can get to the home network securely was a plus.