I enjoyed the movie, but then again I have read and love all four books from the Twilight series.
I think the movie did leave out and/or change a lot of things from the book version, so I think watching Twighlight if you've never read the book may be a less than satisfying movie going experience.
It might be a little hard to follow and understand as it seems to jump from scene to seen out of the book, skipping parts of the book that would explain why things are happening.