Close Encounters of the Third Kind.
I also believe Tron was another?
How did I do, Mingez?
[nitpick]
It wasn't "said" in either one of those movies. The words were shown on signs hanging on walls.
And I'm going to take issue with "Army of Darkness" as well. He never said it correctly.
From Wikipedia
In the film Army of Darkness, the third installment of the Evil Dead trilogy, Ash has to speak similar words in order to retrieve the Necronomicon. He fails to remember it properly ("Klaatu. .. Verada. .. Necktie...Nectar...Nickel...It's an "N" word, it's definitely an "N" word") When he cannot recall what the word is, he attempts to fool the Necronomicon by speaking "Klaatu Verada N-" and then coughing and thus awakens a horde of malicious Deadites. The ending that was chosen for the final edit of the film has him speaking the words again after consuming a potion, allowing him to return to his era. The words were altered from their original use, because of confusion about what they actually were in The Day The Earth Stood Still.
[/end nitpick]