Bella is one of the single most annoying selfish characters I have come across. And the actress who plays her can't act. Seriously, all she does is heavy breathing and play with her hair. The books.... are entertaining if you can deal with Bella being.... Bella.
I will admit to being entertained by the books. And the movies have some fan service so that's ok. There are major plot holes in the general idea of how the vampires interact with society (would you REALLY want to go through high school forever? Couldn't they paint themselves normal? Bella on her period ever?) but learning about the different abilities is pretty nice. And Bella get's less annoying after being transformed.
Ah, but I don't mean to put down the people who enjoy twilight. I'm one of those people too!