In order to fit the current avatars, the picture needs to be of an actor playing a part, not of a real gangster, so you can't have the Krays.
No. 6 wins as he looks like he REALLY means it.
PS. I've mentioned this before, but I'm not sure if anyone has noticed, but could we not just have the male / femal symbol (you know, the Venus / Mars thing) to indicate gender? This would be simple and would get around the issue of female avatars.