In my opinion there is absolutely no reason why any game or movie shoud get a rating above "Mature" or "Restricted" because going past these ratings typically means that you have crossed the line into senseless excess; I will make two exceptions, "Restricted" movies are already too free with graphic violence whereas "Mature" videogames do not give enough freedom in terms of sexual content.
Generally speaking you have two paths when developing a movie/game that will fit into these categories, you can develop the idea in an intelligent well thought out way or you can make it more graphics. Consider Hostel ...
Hostel probably has one of the best ideas to base a horror movie on "If you have enough money there are places which will allow you to do anything" which if it was developed by Stanley Kubrick would have haunted people for generations to come; the unfortunate problem was it was developed by morons who think using make-up to have a girl lose her eye to a blowtorch to the face was a good idea.
Smart people don't need the graphical violence or sex to really push the boundries, they can develop their ideas and get their points across without going to excess; morons need these "tools" and should be punished for being morons.
