Hard to say, really. I like games that have a bit of intrigue that are usually set in modern or near-future times but have either a light sci-fi or crime story elements to them. City of Broken Dreamers is a good example. So is Depraved Awakening. Both made by the same people.
I've not run into a game that does it perfectly to my taste but i do enjoy high fantasy or really just a more medieval realistic setting, not quite realistic fiction, just more aligned with high fantasy
As an idea i really like post apo or fantasy but somehow most of these games that i come around get booring real fast... so i have to say realistic fiction.