From the other BSD thread:
NetBSD
>Installation: curses interface, partitioning by hand
>Documentation: guide takes you step by step (very similiar to FreeBSD handbook)
>Filesystems: FFS
>Ports: (in NetBSD lingo a port is a supported architecture)
>Packages: lots (over platform independent pkgsrc)
>Hardware: BSD of choice for older platforms
>Full disk encryption: not a mature feature, somewhat possible with cgdroot kernel module
>Ease of configuration:
>Firewall: PF (customized OpenBSD version)
>Stand out features: lean and minimal, support for older platforms, kernel lua scriptable, portability, standards conformance is project goal
>Down/upsides: Linux binary emulation, legacy code, easy to get involved via wiki projects, support for ARM boards
>Release cycle: 2-3 years
I installed it on an old MacBook and basically everything worked out of the box, which was kinda unexpected. While I didn't try out the other BSDs on that machine, I'd imagine it would be a little more work. There's even a dedicated driver for old MacBook touchpads. Other than that it's more hands-on (good for people who want to get their hands dirty?), community is very welcoming for people who want to contribute (wiki, drivers, whatever), package system is platform independent, unique purpose is to have an easily portable system and port it to as many platforms as possible, has a large nip community for historical reasons. If you want to get involved it's probably a good choice.
There are things that make it unique, but its maybe not the most accessible of the bunch - is what I found it to be (desktop use). I'm not an experienced user, so take it with a grain of salt. There's at least one other NetBSD user that frequents this board. Solid system for people that want to do more than just "using" their machine.