How about an adaptation of DanganRonpa?
Obviously the name would be different, and have the same sort of theme, but you can totally change the characters looks/names/personality, setting, plot twists, etc.
If done right, I think it has a huge amount of potential success because what I think draws the audience to shows like Game of Thrones and to a lesser extent Walking Dead, is how any character isn't really safe and characters you love could get killed you off. I'm really simplifying it I know but now imagine that, but add in the mystery/detective element, the tension with who's guilty, with no real main character discovered until possibly half way through the show and you got yourself a hit imo.