I've always used Ubuntu with the GNOME desktop environment. I used it as my primary OS for a while when I didn't have access to Windows and I learned to love it. As far as necessary uses (for me that is) it doesn't really have any at the moment so I've not played with it in a while. I'll probably end up installing UBUNTU Phone OS on an old Android device at some point though - it looks like it'd be fun to play with.
What kind of stuff have you been doing with Node?