In Heir to the Empire, Leia goes to Kashyyyk and is greeted by a Wookiee who has a speech impediment that allows him to speak like a human...but she doesn't know about the speech impediment when he first opens his mouth and begins to speak perfect Basic. Since she's only ever met one Wookiee before this, there's a brief moment when she wonders if Chewie was vocally challenged all this time, which he finds very amusing.
Han's Accidental Misnaming moments with the Noghri on Myrkr in The Last Command when they call him "Consort of the Lady Vader" and later "Han clan Solo".
Thrawn's Sarcasm Mode: "Thank you, Ferrier. Your approval means so very much to me."
The exchange between Han and Lando when calling back to the last time Lando flew the Falcon.
The pause symbol vanished before Thrawn could answer; but it wasn't the standard quarter-size figure that replaced it. Instead, a huge image of C'boath's face suddenly glared out at them, jolting Pellaeon an involuntary step backwards. Thrawn didn't even twitch. "Good morning, Master C'boath," the Grand Admiral said, his voice mirror smooth. "I see you've discovered the Emperor's private hologram setting."
Luke and Mara end up escaping a Star Destroyer ("Let's not try going through the garbage compactors."), which coincidentally has also captured the Falcon. After they make their escape, Mara notices a red light on one of the panels, and gets up to fix it. Luke's response? "Don't bother. Han's got this whole ship so crosswired it'll fly with half the systems out."