It has been over a year since I last played Mafia Wars. I collected billions of stuff, and I think it has one truly great educational aspect. As you collect millions of dollars a day, you recognize how big a trillion dollars truly is. Aside from that, I follow Ian Bogost to keep my head straight about what is and is not a waste of braincells with regard to gaming.
His Cow Clicker is a classic meme. Know it.