MythTV distros
From MythTV Official Wiki
MythTV Linux distributions - The fast and simple way to install MythTV
Because of the populairity of MythTV there are Linux distribution available which are dedicated to MythTV. With these distributions installing MythTV is extremely simpel: put the installation cd in to the computer, restart, answer some questions and you're ready.
MythBuntu - http://MythBuntu.com
MythDora - http://www.g-ding.tv/
Knoppmyth - http://mysettopbox.tv/knoppmyth.html
Minimyth - http://linpvr.org/
And there are more...