I found an article that answers that question and includes Cthulhu romance. How can anyone pass up Cthulhu romance?
http://www.cracked.com/blog/the-vampire-formula-what-women-see-in-them/
Edit: Batman is in the same article! Awesome!
http://www.cracked.com/blog/the-vampire-formula-what-women-see-in-them/
Edit: Batman is in the same article! Awesome!