There are so many good ones but here are a couple that came to mind when I saw this question:

From RotJ: “Never. I’ll never turn to the dark side. You’ve failed, your highness. I am a Jedi, like my father before me.”

From ESB: “I don’t believe it!” “That is why you fail.” plus Yoda’s “luminous beings” speech.

From Andor: Kino Loy’s “one way out” monologue over the intercom during the prison break.