She practically dies anyways.
For me the battle between best film is always between 8, 3, and 4. The final film usually takes first because it has the best balance of style and pace.
I actually prefer the treatment of the final battle between Harry and Voldemort in the film, it lacks some detail, but it has much more personality. It really portrays Voldemort as this sort of sad, desperate creature (Which to me said more about him then all those flashbacks in book 6), were as the novel took the "love" magic concept too literally. If I was Voldemort I would just shoot Potter the moment he started that long exposition in the novel.
Oh yeah, the fifth movie is really off. The sacrifices it made really scarred the series. The Neville thing doesn't bother me that much, because by the finale he really becomes the 'heart' of the series, centered on that fantastic speech against Voldemort.
—on the note of the 5th film, and 6, the lack of that one Snape detail really took way from his story.