For starters, I read the Inheritance Cycle. I started reading it because some people that I know really liked it. And I was drawn right into it.
Let me tell you, I'm a real sucker for adventure. And that's why I have to be extra careful when I read a book. If I'm not, I'll like it simply because the battles are really awesome, or there's amazing adventure in it. And I tend to brush aside the 'other stuff'...that matters much more than adventure.
Sure, I was bothered when Angela predicts Eragon's future, the Elves declare themselves atheists, that the magic is not an allegory of God's power (as it is in Lord of the Rings and The Chronicles of Narnia) and that Eragon's love for Arya is more of a lustful crush than real love. But I just ignored it and tried to convince myself, "Well, at least it doesn't have any 'good' sorcerers or anything like that in it."
And then I realized that Eragon and the other riders are basically sorcerers by another name.
After that, I started noticing other things such as Roran and Katrina's disgusting relationship before their marriage. And the book didn't even portray it at wrong! At the most, it was only 'different'.
And that lead to me thinking, "How different is Eragon from Twilight?"
Yikes.
Okay, I have never read Twilight, and I'm not sure if I will. If I do, it will be mixed in with hours of reading my Bible and praying, and it will be when I'm much older. But a Christian review that I read a long while ago (and that I can't find right now...sorry!) said that Bella lies and forsakes her parents for the vampire-dude, who I think is named...Edward? Yeah, anyway, for all of you who have already read Twilight, is that true?
If it is, then wouldn't 1 Corinthians 13:6 apply here? Love does not delight in evil but rejoices with the truth (1 Corinthians 13:6 NIV) You may argue that Edward (if that's the vampire-dude) is a good vampire, but is he really?
If you have read Twilight and know that I have the facts wrong, please correct me.
Avoid every kind of evil. 1 Thessalonians 5:22 NIV
Love must be sincere. Hate what is evil; cling to what is good. Romans 12:9 NIV
Let those who love the Lord hate evil. Psalm 97:10A NIV
And because of those verses, I am considered whether or not I should read the last book of the Inheritance Cycle.

P.S. HERE is a review on Twilight. Not the one I was looking for...but I would still suggest it.