Change the ending of a movie to make it better

Glass kills Fitzgerald.

Krennic lives, then Vader chokes him out for allowing the plans to be released. This was actually just the original ending before it was changed.

Lee Marvin's character dies, leading to a large memorial at the end with Jim Brown's character (who lives) and Bronson's character. It would've made for a more affecting and emotional finale with some heft.