I'm going to start by saying I read the first book when I was in high school, and loved it. I read the second book, and hated it. Then someone told me to try the third, so I did, but I wasn't a fan. I made it half-way through the fourth and gave up. I'd seen part of the first movie before, but it didn't look great, so I never thought to rent it.
Over the weekend my roommate borrowed all three movies from a friend and had a mini-marathon. Twilight was OK, if not a little boring (I mean, half the movie is just Edward and Bella looking at each other). The book was appealing because of the whole sort of day-dreamy mood we got by being in Bella's head, but it just didn't translate to screen well. It was a book about emotions, which is hard to base a movie around.
I skipped New Moon because I disliked the book so much.
And then I tried eclipse because I'd heard it was much better and... it was much better! I was pleasantly surprised. It was neat to see more of the other Cullens and their backstories. Bella still annoyed me, but other than that, there wasn't much to complain about. It felt a little more balanced between the romance story-line and the supernatural plot, which I personally think made the romance part more valuable.
I'm curious to see what other people think. Any twilight fans? Twilight haters? I'd be curious to know what's so appealing about it, or what's so unappealing.