There's one thing I've realized this time. As far as I know, people have loved these books because they are the "universal perfect romance." I've always had a bit of a hard time with that concept, and now I've pinpointed why: It's not the perfect romance, but it IS the perfect fantasy. Everybody has experienced that entirely-out-of-your-league crush. The one boy in high school that makes you swoon just by looking at you, and makes you totally tongue-tied and sound like an idiot. This describes Bella's feelings for Edward perfectly..... except in this fantasy world, the out-of-her-league crush actually RETURNS her feelings. And what woman (or man, for that matter) hasn't wanted to feel loved and adored- or even noticed- by that one crush? Stephenie Meyer does a good job of descriptive writing, and pulling the reader into the emotions of the book. So readers get to live vicariously through Bella, experiencing the thrill of feeling special and noticed by someone who otherwise wouldn't be giving them the time of day.
Well, those are my thoughts on the matter, anyway.