Depends on what you need.  If you want  box that can do some pretty advanced routing, tie in  dialup backup, even support remote dil-in (out of the box) freesco is great.  Freesco, however, is not the easiest to set up or configure, and to my knowledge does not yet provide a web based interface for administration.
Smoothwall on the other hand, which I have been using for about a year now, takes about 5 minutes to set up, has a decent web interface which makes administration easy, and does everything your typical cable/dsl router can do.  Port forwarding, DMZ (a TRUE DMZ, not that crap that linksys and netgear call a DMZ), logging, etc.
That said, I would vote for Smoothwall.  Note: stick to the 1.0 series until 2 is out of beta.  I may just be paranoid, but I wouldn't trust my network to beta software.