Twilight as a meme: "The Nobel Vampire"
One definition of the word ""meme", is a work of art which is so influential that it alters the impression of a concept. In "The Twilight Saga" Stephany Meyer created a powerful new meme: "The Nobel Vampire" and in doing so she altered what we think of when we consider Vampires.
Part one: Can you think of examples (in currently popular books, movies, or TV) where other writers have adapted their characters to Stephanie Meyer's new "Nobel Monster?"
Part Two: How is Stephany's "Nobel Vampire" different from other "Good Beasts, in previous stories" ?
To answer the first part of your question, so many books in YA fiction are following the "noble monster" trend now. Maggie Stiefvater's Wolves of Mercy Falls trilogy, for instance, is an example that features a romantic "monster" hero and his beloved human girlfriend. While there are differences--the threats to their happiness in Twilight are predominantly supernatural while in Stiefvater's works the obstacles are largely societal (bad humans vs good monsters), for instance--there are also enough similarities to support these books as part of a larger trend.
In all honesty, I believe that what Meyer did with vampires is really following a path iin fiction and especially in fantasy fiction that has been brewing for years. Quite often in fantasy fiction it is the monsters or, in many cases the human freaks, who are noble while the normal or the powerful in society are corrupt. Think of Game of Thrones, a series which George R. R. Martin has been writing for many years. One could say that the celebrated and beknighted Jaime Lannister is not nearly as noble as his brother Tyrion the imp.
This trend is not new. The movie E.T. featured an alien who was gentle and kind versus the humans who would exploit him.
Popular entertainment has many examples of this type of "other" vs mankind story where it is the humans who are less than noble. One current example which is particularly relevant to Twilight is the TV series The Vampire Diaries. The vampire characters in this series range from angelic to evil, but they all have a common enemy--the townspeople of Mystic Falls who have been hunting them for hundreds of years. While there are many, many differences between Twilight and TVD, there is still a common element--humans, especially the adult ones, must not find out the truth. This is a trend in YA fiction especially--it is the younger generation who are most accepting of these "others" and the older generation who generally seeks to destroy what they do not understand.
Stephenie may have been among the first to give vampires the "noble monster" treatment. But I honestly don't believe she started the trend.