how about a game where you play a normal guy who has been lifted up to supernatural prowess. it has an open ended story, but several paths lead you down an enthralling story filled with loss, sacrifice, and deep, interesting characters.
Oh, and if you're evil, you can rob gas stations, banks, ect. while, say, pausing time, or spraying fire and lightning everywhere.
P.S. make it a true sandbox, don't put cheap things in the way to keep them from going places, and actually give them freedom, not just an illusion of it.