"There is no charge for awesomeness." (Beat.) "Or attractiveness."
When the "Legendary Warrior" Po encounters the Furious Five:
Master Monkey: We should hang out. "Legendary Warrior": Agreed.
"I love Kung Fuuuuuuuuuuuuuuuuu...!"
The candle-blowing scene. Oogway has something important to tell Shifu, but decides to start blowing candles out... one... by... one. The only thing funnier than Oogway seemingly preparing to continue speaking only to keep blowing them out would have to be Shifu's understandably irritated expression.
Shortly after that, Shifu and Oogway contemplate who will receive the Dragon Scroll:
Shifu: But who? Who is worthy to be entrusted with the secret to limitless power? To become...the Dragon Warrior? (beat) Oogway: I dunno.
On his first day of training, Po suggests they start with exercises suited to his level, like "level zero"; Shifu says there's no such thing. Later, Shifu gives an evaluation to Po's totally un-awesome display: "There is now a level zero."
After Po smashes the urn of whispering warriors, the collected souls moan every time Po nudges the pieces.
Po: Oh. 'Kay. (long Beat) Wanna get something to eat?
Shifu(with long-suffering sigh): Yah.
Especially with how his eyes go wide open, implying that's Shifu's also a Big Eater.
At the climax, Tai Lung hits Po with the nerve strike attack thingy and he keels over...only to start laughing when Tai Lung keeps punching him. "Stop it! I'm gonna pee! Don't!"
From the tie-in video game: Po is hopelessly lost in a desert while trying to get back to the Jade Palace. He comes across Tai Lung's secret training ground and comes across Tai Lung himself (either him or an illusion, it isn't made clear).
Tai Lung: "Why have you come to my training ground?"
Tai Lung foreshadowing his eventual humiliation at the hands of Po: "What are you going to do, big guy? Sit on me?" Why yes. Yes, he is. Repeatedly. All the way down the stairs. For extra points, there is a loving slow-motion zoom at Tai Lung's shocked/pained/humiliated expression as Po squashes him at one point.