Okay, with that out of the way...
Even though the writing wasn't stellar, I continued reading the books and recommending them to my students. These books definitely strike a chord with teen girls, especially reluctant readers. And then came Breaking Dawn. Getting to the end of that book killed the series for me. I have not recommended these books to a single person since.
A message that young girls (and fully-grown women) do not need is that they are not important, that their only purpose in life is to have children and sacrifice themselves for everyone else. I ran across this humorous article with summaries of how Twilight might have been written by famous authors. The following, Twilight by Dr. Seuss, was posted in the comments below the original article. Not only is it hilarious, but it will save you a lot of time if you are curious about the books, but don't want to slog through them.
Twilight, by Dr. Seuss
Jake likes a girl. Her name is Bella.
Bella likes a different fella.
Bella likes a different fella.
See this vamp? This is Ed.
Ed is pale. Ed is dead.
Ed is pale. Ed is dead.
Ed saved Bella from a van.
Ed must be a special man.
Ed must be a special man.
Ed won't kill boys. He won't kill girls.
Ed gets fed on deer and squirrels.
Ed gets fed on deer and squirrels.
This is James. He's a tracker.
He's a sort of vamp attacker.
He's a sort of vamp attacker.
James hunts Bella for a thrill.
Will Ed kill him? Yes, he will.
Will Ed kill him? Yes, he will.
But James gave her a little bite.
Will she be a vamp? She might!
Will she be a vamp? She might!
Edward fixes Bella's cut.
She won't be a vampire.
But...
She won't be a vampire.
But...
She becomes one. Read some more.
She's a vampire in book 4.
She's a vampire in book 4.