One of the important distinctions between literary fiction and romance is that in the latter, you usually like at least one of the characters. In literary fiction, enjoyment of the book isn't predicated on whether or not you like the protagonists.
But sometimes there are romance novels that read more like literary fiction—where you like the book, but don't particularly like the characters. With the advent of 'edgier' books hitting mainstream readers, this situation is becoming more commonplace.
What romance novels do you think are good, despite having characters who aren't totally likeable?