I just finished watching the movie over the weekend. All I can say is that the Twilight story reminds me of the Roswell TV series. Here is a list of common things I noticed between the two series:
1. Both female protagonists (Liz Parker and Bella Swan) are high school students who nearly lost their lives. They were in the wrong place and in the wrong time. Both girls who have died, except they were saved by their respective crush (Mr. Vampire and Mr. Alien).
2. Both female protagonist experience a strong attraction to their respective crush -- to the point of sacrificing everything they have just to be with their out-of-this-world boy friends. In the end, they became vampires/aliens themselves.
3. Both shows have sheriffs acting as distant father figures.
4. Both shows deal with a "family" or "group of related" aliens/vampires, who were forced to accept high school girl because of her strong/passionate connection with alien/vampire boy.
Watching Twilight made me think of Roswell and I couldn't help but feel that Stephenie Meyer borrowed/used some of Melinda Metz's ideas.
I would not suggest comparing the movie to other vampire flicks. Twilight was written to be a love story for young adult writers. It steers away from excess violence, bloody gore, and horror. The story focuses on Bella and Edward's relationship, mirroring your typical high school romance (mixing with some supernatural elements).
Overall, I had a good time watching the movie. The story was a bit predictable (even without reading the book) but the characters are interesting enough for you to want to watch the sequel.
(Review copied from My Seven Lives)