For several years I was able to use a Netscreen-10 that I bought off Craigslist for the fairly simple network infrastructure at my house. I need to be able to deal with a few static IP addresses and a few custom rules for VPN traffic. Up until about four months ago the pre-Juniper Netscreen-10 unit chugged along like a star. I actually computed out the MTBF for it, and it went three years beyond what it was designed for. It kept crashing twice a day when my wife's VPN traffic was really heavy, so it had to be replaced.
So, my issue was what to replace it with. Should I go with Cisco, Linksys/Cisco, Netgear or some other flavor of the week at Fry's. What I end up with is not what I expected. I ended up loading Smoothwall on a mini-itx based PC using a IDE to CF converter. So I ended up with something that didn't cost me a penny (I already had the hardware lying around) and outperformed my previous installation.
Smoothwall fit the bill and was free. I'm sure that IPcop or m0n0wall would work just as well on the exact same hardware. Smothwall is pretty cool in that it provides a snort engine for intrusion detection, which is really helpful in fending off cyber attacks.