Like others have said, being unbiased is difficult, but I'll try. First, Linux v FreeBSD is really tough, so I will instead approach this from Debian v FreeBSD. I really like how easy Debian on the desktop is: install it, apt-get install xfce, and I have a nice desktop. It's very easy to add Adobe Flash, Steam, Skype, etc. The FreeBSD desktop isn't as nice. You can add things like Flash and Skype on FreeBSD, but you…
What stopped me from using FreeBSD a year ago was lack of automatic tab completion on the shell. I would like to try FreeBSD again. Does anyone know if this works now? edit: clarified the reason I ask is because I want to know.
Personally I run Ubuntu on my work desktop so I can focus on work and not managing the OS. I run a private irc server on a busted old desktop running Arch Linux for the opposite reason :)