I agree with Tosa. I think that you should have the board avatars until you reach a certain post count like 500 or 1000 but then you are allowed the privalege of using your own custom avatar if you wish. However they have to inkeep with the .org's atmosphere as so many have mentioned.
I agree with what has been said above though that the .org wouldn't be the same if people had mickey mouse avatars etc. They had to b something to do with the total war series.

However after writing this now I and reading what all of you have put I am not so sure I agree with myself, to be honest now I think that I would prefer the standard .org avatars.