I honestly prefer the book more, but the movie wasn't bad. Although, I hear many say that this is the best movie they've ever seen, but I think that's only because girls (which are the biggest fans) are in love with Edward Cullen and Jacob Black. I am not afraid to say that I don't have "crush" on them, which helps me to see that this film need some improvement.
The movie lacked some vampire-ness and it focuses more on Bella Swan's desperate need and love for Edward, and I think that's fine, but not enough to make a fantastic movie. There are many other vampire movies out there, that does deliver some blood and bite (yet not too much gore), but I guess Twilight was good enough for teens and adults to see.