Jules Jones

That's an interesting essay, but I would suggest that it's possible to be more objective than she claims. Beyond what she calls correctness are things like: is the language fluent and are there vivid descriptions of character and setting? Is there some originality in the language, for example in the similes and metaphors used, or is it full of hackneyed, over-used phrases? (Language can be grammatically correct, but full of boring cliches.) Is there a good balance between narrative summary (telling) and dramatised scenes (showing)? I would say that these features are pretty much independent of genre.

I also agree with shriker_tam that believability comes into it a lot, whether it's lit fic, fantasy, romance or whatever.