I tell you one hack I would love to see, is a Victorian/Sherlockian themed hack, were you get to play James Moriarty, Sebastian Moran, Edward Pierce, Robert Agar. With playbooks like snakesman, cracksman, screwsman, bludgeoner!
http://www.tlucretius.net/Sophie/Castle/victorian_slang.html
Maybe with a steampunk twist, I would love it set in 2000AD’s Stickleback’s London