I'm a BSD
This week I am taking FreeBSD 8.0 for a spin. So far, I like it enough that it will probably be my normal desktop environment. It seems to have the right stuff: my PC seems markedly faster.
FreeBSD's slogan is The Power to Serve and that is a good summary of where the strengths and weakness I have found lie. The installation assumes that you are installing a server, and then configuring it for desktop use: there does not seem to be a way to configure, at install time, that the user wants to use a fancy window system even.
So I think anyone without previous UNIX experience would be well-served to try one of the out-of-the-box consumer distributions of BSD: PC-BSD looks good. Otherwise, you may find some major individual applications require a little bit of detective work to install: I found this puzzling because I thought FreeBSD had a great reputation for having everything work.
FreeBSD has two built-in ways to load software sourced from provided servers on the Internet.