Given I read mostly historicals, a strong sense of time and place is really important to me in whatever I read. Fluff and wallpaper historicals have their place, but I like an historical to pay more than lip-service to the monicker.
Smart-mouthed damaged heroes.
Intelligent, dignified heroines who give as good as they get without being curl-tossing TSTL foot-stampers.
Sexual tension off the charts. Some authors can do more with an accidental touch or kiss than many can with an entire sex scene. If the tension is good, then I don't need to read explicit sex scenes.