A Definitive List of Gaming Genres?

An anonymous reader puts forth this challenge for the Slashdot readership: "Construct a definitive list of game genres for PC and/or console that doesn't dribble off into silly categories like 'licensed movie franchise,' or include redundancies like 'action', '3D adventure' and 'platformer.' My friend and I have been messing around with this for awhile, trying to do a better job than the game news sites, but we're finding it's harder than we thought."