BSD? It passes the Hairyfeet challenge with flying colors, too bad there simply isn't enough consumer hardware support for it to be a viable desktop.
If your challenge doesn't take into account consumer hardware support, it's not a very good challenge. Consumer hardware support is one of Linux's greatest strengths, especially as compared to BSD. The software support is pretty relevant, too. I'd probably have jumped ship by now (I have nVidia, they have an OK BSD driver I'm told) if I could have vmware. It's the only vm with good 3D support. So since I'm sticking with Linux, I just went ahead and adopted KVM as my VM strategy. Now I'm more or less married to it, although obviously I could migrate away again. I migrated my non-3D-using Windows VMs to KVM already, I could likely migrate them again given a reason. But what's OSS and better than KVM with SPICE? Virtualbox would be if 3D didn't make it asplode every time I tried it.
But if you truly believe what you are saying? Then put your money where your mouth is and take the Hairyfeet challenge which just FYI only requires Linux to run HALF, I repeat HALF as long as a Windows lifecycle.
I've been running "more or less" the same Ubuntu install since Dapper Drake. There was a complete reinstall in there somewhere around Karmic Koala, but I kept my homedir, /opt, and /usr/local. Also, in the same time, I've had to reinstall Windows about a dozen times for one reason or another. And many of my peripherals showed up cheap (scanners, printers, etc) because Windows dropped support for them. Yeah, not Windows, the vendors, but same difference to the user. New windows, new scanner. Thanks, Obama^WHP. Man I can rant about scanner drivers all day, how sad