Sounds like what Martin did with Song of Ice and Fire. Its like a mystery/political/historical fiction fused with a light tapestry of fantasy. Very gritty adult fiction. There's a joke between myself and my friends that he really wanted to write some porn, and disguised it as fantasy. The sex scenes are not graphic though. Just more than you would expect from fantasy.
'A Game of Thrones grabs hold and won't let go. It's brilliant.' -Robert Jordan