I know you already mentioned Amsterdam in your post but it has the widest selection hands down. I was there last year and I can speak from experience. You will find whatever you are looking for there Take a look at onlytravels.net for available rooms at fantastic prices.
Rio de Janiero. Even Fodors travel book once said Rio had the best looking prostitutes in the world and the selection is amazing.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.