On my 3 VPS's i run ubuntu or debian (since they don't offer FREEBSD on openVZ VPS's).
If i had the chance, i'd use FreeBSD, i like the way it works (the webserver at my office that i set up is running nonstop for over 6 years now).
All my desktops and laptops run windows, since they're all company property, and i'm not allowed to change the OS
:. I'd probably go for debian or freebsd if i had the opportunity