Darth Vader: Obi-Wan never told you what happened to your father.
Luke Skywalker: He told me enough. He told me you killed him.
Darth Vader: No. I am your father.
Luke Skywalker: No. No. That’s not true. That’s impossible!
Darth Vader: Search your feelings. You know it to be true.
Luke Skywalker: No! No!
From the movie Star Wars: Episode V – The Empire Strikes Back (1980)