Which one is currently the best version of Linux with easiest graphical interface and which software is best to install on a PC and use as dedicated video/media player?
Don't really need all the extra bells and whistles. Just a generic mainstream Linux distribution, e.g. Fedora, Ubuntu, etc. and some good software as a media player.
where XMBC took Ubuntu and slapped XBMC on it, Openelec took XBMC and built just enough OS under it to make it run on most hardware. Thus its about 8 times smaller than XMBC live.
Last time I played with MythTV was just after the gnome distros switched to PulseAudio - to say trying to set it up was akin to mud-wrestling with an alligator is a understatement.