My sister's reading through Twilight right now and we're discussing it, and suddenly, about ten minutes ago, I realized what the book reminded me of.
A yaoi manga.
Edward/Seme: Gorgeous, talented, amazing, flawless, but also unbalanced and obsessive.
Bella/Uke: Faints, pines, possesses an inferiority complex the size of Manhattan despite the seme/sparkly vampire's obsessiveness.
Holy shit, you guys.