I am currently reading the Twilight books, or... well, I just read the first two.
If I had known any better, I would've stayed away from them. I'm 20 years old, and I find them very depressing and disturbing and a form of chick-inappropriate content. Bella is easy to identify with because her character is so vague... this is why it is so dangerous for girls to read them... it's so easy to want to make yourself feel like her, and when she gets the attention she does from such a "beautiful" and "god-like" creature as Edward the vampire.
In the first book, it is not as harmful, but still quite bad: it's true she is very dependent on Edward, but the problem is exacerbated when you think about how she is willing to lose all of her friends and completely become absorbed in him, losing all other parts of her life (not that there was anything substantial there in the first place).
I find the second book to be much worse, and here is why I do not think any teen (or even me in this case) should read them:
1. Bella is depressed, zombie-like, masochistic, and self-harming (not to mention selfish as she puts herself in danger constantly, despite her parents and her couple friends that care about her). This is because Edward leaves. THIS KIND OF BEHAVIOUR SHOULD NEVER BE ALLOWED OR TOLERATED OR ENCOURAGED BASED ON INFATUATION!!!! I deal with depression and it is a terrible, evil thing. I KNOW what it's like to go through similar things as this, and it cannot be made into a fairy-tale and seem okay because there's so much romance. Getting caught up in romance can lead to awful things if you don't keep your wits about you... especially if you're as emotional as me, or as hormonal as a teenager!!!
2.Bella wants to become a vampire even though she knows that there is a possibility that her soul will be "condemned to eternal damnation". There is not a lot of discussion about this, but the idea recurs many times, and she continually argues with Edward that she doesn't care about her own soul and is more than willing to become a vampire despite the possibility of, when she does die, going to hell.
3.And yeah, Stephanie Meyer (author) may be a Mormon and therefore doesn't insert any sexual intercourse within the novel, and sure the kissing scenes are sparse... but the obvious problem is that Edward is a vampire, he desires her blood. And obviously Bella is extremely desirous of him too. The lust that emanates from this is so sickening... Also, sex is not the real problem, it's the fact that they are not actually loving, caring individuals... they are obsessive, horny, selfish, mopey, hormonal (yes, even a vampire over 100 years old can apparently be hormonal over a 17 year old girl), and with no regard for wisdom or the future.
THESE ARE TERRIBLE MODELS AND IMAGES TO PUT IN ANYONE'S BRAIN!!!!!!!
If you don't want your young son to play violent video games for fear of it callousing them, you won't want your young daughter to read this books for fear of what it will callous them with emotionally, not just in terms of romance and self-esteem etc. etc. but in terms of their soul.
And when all that is said and down, if there is no other reason not to read these books, it is that they are a waste of time. If there is nothing edifying in them (let alone destructive), it is wrong to spend 12 hours reading them.
If we live, it's to honor the Lord. And if we die, it's to honor the Lord. So whether we live or die, we belong to the Lord. Romans 14:8