He was Legend

The book I am Legend is told in the third person. However, it involves such a close, and at times intimate, narrative that it almost seems like first person. Neville is the only character, and so we may forget that the narrative is not actually told through him, but from an omniscient narrator.

The film I am Legend contains a small narration at the end:

"In 2009, a deadly virus burned through our civilization pushing humankind
to the edge of extinction.Dr. Robert Neville dedicated his life to the discovery of a cure and the restoration of humanity. On September 9th, 2012 at approximately 8:49pm he discovered that cure. And at 8:52, he gave his life to defend it. We are his legacy.
This is his legend."

This small portion of the film is the only part told through a narrator. In this case, the narrator is Anna. I find it interesting that Neville is still the legend in this case, however the term legend takes on a different meaning. Because Anna is still alive, and is a human narrator in this case, the legend of Robert Neville is quite different than it is in the novel. In this case, Neville is a hero among mankind. He will be remembered perhaps like Alexander the Great, George Washington, or another legendary human. The novel paints a much more chilling picture. Neville is a legend, not like like George Washington, but rather like the Loch Ness Monster or bigfoot. He is a villified monster, the only one of his kind and a feared creature to the whole human race.

I find that this is the greatest difference between the film and the book, and for this reason greatly preferred the telling of the story in print, as it has really stimulated my thinking on what it means to be human and a member of humanity, while the film resembles just another Hollywood story of an improbable heroic individual.