BSD is often a good choice for utility boxes running stuff like Sendmail or BIND. The hardware support isn't as good, and if you think desktop applications are bad with Linux, then you certainly aren't going to like BSD. BSD is arguably more secure and stable than Linux. In the gradient of stability, though, Linux and BSD are much more stable than some very popular commercial operating systems. :)
There are several BSD versions out there. Here is a fabulous comparison between Linux and FreeBSD. We chose OpenBSD, but FreeBSD is another good distribution.
For those of you with a little money, support OpenBSD, and purchase your CDs from the official OpenBSD site.
We have almost no money, so we found some OpenBSD iso images. Wait til you see the machine we used. :) We used a simm extender with 30 pin memory from '91!!!. We are cheap!!! And, that is the beauty of the perspective of NetAdminTools, no? Anyway, here are some sources for OpenBSD iso images:
Be careful where you get your OS images, you'll never know what you'll catch.
The best installation instructions we have ever used are the instructions for installing OpenBSD here. They rock! Everything was as claimed.
When you get to the timezone question, enter ?, enter the region, and then enter a ? again to find the specific part of the region.
All in all, this was one of the easiest OS installs we have ever done. Quick, painless, good docs. A tip of the hat to OpenBSD.org for a job well done.