Here's something about the popularity of the Twilight series that those who hate the books never, ever, ever seem to get (or maybe they simply ignore it, because I think it's hugely obvious):
At its core, it's about two people -- okay, a human and a vampire, to be exact -- both very wrapped up in their issues and insecurities and (what they see as) individual weirdness, but who click together in that unexplainable way that love has.
Which means that when they fall in love, each of them is thinking How did someone as weird, off, and odd as me find this other person? How do I deserve this person? How was I lucky enough? And each thinks he or she has gotten the better end of the deal.
I see that all the time in real-life couples. They love each other, and at some level they keep being amazed at their luck that this amazing other person loves them. But love, as I've seen, encompasses the weird, off and odd parts of the person you're in love with. Otherwise, the confession near the end of When Harry Met Sally wouldn't ring true. (I adore the line "I love the little crease you get in the middle of your forehead when you look at me like I'm nuts!")
I've cited it before, but in the suspense novel Brothers, William Goldman's insanely cracked-out sequel to his novel Marathon Man, there's a moment that encapsulates this. We meet a young married couple in love. She had long been insecure about her rather large birthmark. She flashes back to when she and her future husband were falling in love, and they saw each other naked for the first time, and he saw her birthmark and said casually "I wish I had a birthmark." He inadvertantly said the exact right thing that got her to be not so insecure about it. That got her to be more comfortable with it.
I like it when love causes comfort like that.
Good Will Hunting has well-said truth in it, like this: "You're not perfect, sport, and let me save you the suspense: this girl you've met, she's not perfect either. But the question is whether or not you're perfect for each other." And in the knowingly melodramatic world of Twilight (a series I maintain has far more of a knowing sense of humor to it than its non-fans think), Bella and Edward are that kind of couple.
There are other things to argue about Twilight, because there's more going on than that. Yes, it is creepy and stalkerish how Edward often expresses his feelings for Bella. Yes, Bella has issues that she doesn't think through enough, leading her to do stupid, dangerous things. Yes, the plot in the first two books takes too long to really get moving. Yes, Jacob has his own issues to confront. Yes, Stephenie Meyer is still learning how to write.* But there's a core truth that Meyer hit on, and even if she hit on it inadvertantly, it's there. I just choose not to ignore it.
* I'll defend Meyer this way: Not everyone is capable of becoming a writing machine. Except for Twilight, Meyer's four other published books and her half-completed first draft of her Edward-POV novel, all heavy with words, have been written in the last four years. She's learning her writing lessons in public. That takes courage, plus an insane confidence that she can pull it off. And everything I've seen about Meyer suggests to me she's keeping her perspective amidst the insanity of both the popularity and the "WHY is this popular?!" incredulity and hate these books have also fostered. She knows she has a lot to learn. She's self-effacing about her success (and able to joke about her lack of cooking ability) and good at crediting those who've helped her. In the end, her best argument for longevity -- which she may earn, which she may not, there are too many variables to determine that now -- is getting the words out and making them worthy words. She got an enormous break with Twilight's success, same as what Stephen King got with Carrie. King kept delivering. I think Meyer has the potential to keep delivering, too. And I prefer to see the potential to be better.