Runescape, it's the most famous one out there actually. But the downside of Runescape is that you cannot make real cash from it.
There are many different virtual world communities available online based on different interest. Aside from the ones you mentioned, other popular virtual worlds include Runescape, Ourworld, Cybertown, Woozworld, Webkinz World, Club Penguin, SecretBuilders, World of Warcraft, TappedIn, and WorldFlirting. Source: http://www.virtualworldsinfo.com.
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.