NetBSD is my personal computer OS. I can hear you ask, "Why, why would anyone use such an obscure, hard to use OS?" Well, I started out using GNU/Linux. I switched because I wanted to use a Unix-derived system, just for fun.
What I found was a high-quality system, without all the bloat of conventional Linux setups, yet including everything you need to get started (Slackware is the best Linux; before I switched to NetBSD, I had actually done Linux From Scratch, to have an OS that suited me, but keeping up on security and changing makefiles to work on my system got pretty tiring). Want more? There's pkgsrc, a whole tree of packages that you can download (precompiled or from source), that can suit almost any need you might have (right now, I'm downloading Gnome from source). Best of all, it automatically downloads packages that are required by the package you want.
The NetBSD philosophy is to write good, clean code, not quick hacks. They care about security just as much as OpenBSD (or more so), they just don't brag as much. All of the many NetBSD ports require that the code be written cleanly (so it will compile on all of them).
I love NetBSD.