Tigress: *proud* That was funny, wasn't it? It has meaning on two levels: You can't meet them because they're an abstract idea and you WON'T because you're laz-
Po: *unamused* Yeah..okay, now you're just wrecking it.
In the "Love Chain" Tigress crack two jokes and didn't realize it.
Monkey:Shifu is just rehearsing his (pretend to sleep)Autumn Festival speech.
Tigress: Oh yeah that remind me, I need to practice sleeping with my eyes open.
The other furious five laugh at that.
Monkey: Good one.
Tigress with confusion: What?
Monkey: Skip it.
Later on in the episode when they wonder where Po is.
Viper: Maybe he is bonding with his dad new girlfriend.
Tigress: Or more likely he is bonding with a bag of almond cookies.
Monkey: Good one again.
Monkey: Skip it.
Also from "Chain Reaction", there is a brief moment where Po attempts to distract one of the alligator bandits who have kidnapped Tigress. On his first attempt, Po throws a pebble at his head, but the guard does not acknowledge it. On his second attempt, Po throws a significantly larger rock; this time it lands right between the guard's eyes, at which point his pupils drift apart from one another; all the while the guard remains unphased with a stoic expression. Cut to Po with his mouth agape in disbelief.
Once Good!Po recognizes his Synchronization with "Bad Po", he goes... rather overboard in exploiting it.
Almost the entirety of "Master Ping". Notable moments are: Ping's telling of the "greatest noodle-maker in China", his turning the Five (and even Shifu, briefly) into his waiters, his laughable attempts to train the pig warriors, and his ineffectual fighting with Po while trying to explain to him his mistakein teaching a real kung fu move to the pigs.
Peng's imitation of Po, and it helps that it's actually pretty accurate.
The entirety of Po's Disguised in Drag bit from "Ladies of the Shade". Particularly when he is forced to dance, and when the foot of Crane, who is hidden under the back of his dress, is confused for Po's during the pedicure.
Po's idea of wooing a lady by showing off his butt in the shape of a heart...and it working.
Po: I showed you how my butt looked like a heart!
Song: Something I will always treasure!
Po: I, uh, have a little something for you... *hands Song the sketch of a heart with a cross through it*
Song: I will always treasure it.
Po: It's my butt.
Song: I know. *kisses his cheek*
When Po brings Bian Zao's last cake to Tao Tie.
Po: ... Is this awkward?
Tao Tie: Not at all! I have loads of archenemies who bring me baked goods!
In "Owl Be Back", Po's shocked to learn there were previous generations of the Furious Five, despite the group having protected the Valley for ages:
Shifu: How old did you think Tigress was?
Po: Iunno, like forty-ish?
"Ladies of the Shade" has this exchange.
Tigress: I don't trust them.
Monkey: You don't trust anyone! Not even the mailman, and he's been coming here for thirty years.
Tigress: Planning something for thirty years.
In "Challenge Day", Shifu has decided to send the Five off to a spa for rest and relaxation. Tigress asks what that is, Shifu starts to explain, and then...
Tigress, with utter seriousness: No, what is "relaxation"?
Crane, gently taking her by the shoulders and leading her away: I'll explain on the way...
And after they return home...
Tigress: Well, that was a complete waste of time.
Mantis: It would have been a lot more fun if we could have stayed longer, instead of getting kicked out.
Tigress: He came at me with a weapon, I was only defending myself.
Crane: It's called a towel.
Shifu and Po kept saying an apple for thirty seconds.
Po's incompetency when he and Shifu were trapped in stockades in 'Bad Po'. To elaborate, not only was the key in easy reaching distance but his stockade wasn't even locked.
The entirety of "My Favorite Yao", from Po calling Shifu on his messing up, to Shifu having to do things Po's way, to all of Yao's Sensory Overload experiences. The absolute crowning moments, though, would have to be Po catching Shifu playing with his action figures of himself and Yao and Shifu's fan dance, complete with coquettish flirting.
Earlier in the episode, upon seeing Shifu's excitement over Yao getting closer:
Po: Master Shifu? You okay up there? You seem a little... Giddy.
At the start of "Monkey in the Middle" Mr. Ping and several villagers arrive at the Jade palace. Mr. Ping states their purpose in his usual tone.
Mr. Ping: Po, is Shifu at home? The angry mob and I must speak to him at once.
In "Terror Cotta", the Running Gag of the Shared Family Quirks which Feng and Bing have. Also, his poor gang's attempts to learn something productive and legal from Po.
They even called Po a penguin!
When Po discovers Shifu has not only come to the Festival of Figurines when he declared it a childish, frivolous pastime that no self-respecting kung fu fighter (especially the Dragon Warrior) would go to, he's there using his Master Yao action figure to fight with the other Otaku. And then he tries to get out of it by claiming, just as Po had, that he was just "someone dressed like" Shifu.
Also Ping selling his son's underwear among the Dragon Warrior memorabilia.
The Five, particularly Tigress, catching Po playing with his action figures.
Shifu and Po constantly writhing around while trying to rescue Mantis, thanks to Taotie's mechanical action figures attacking them.
Shifu acting like a hyperactive kid in "Shifu's Back".
"Mind Over Matters", When Po accidentally reveals that Mantis wonders why Viper never wears clothes, Viper asks where's his clothes. Mantis points out it was just an observation and he uses Tigress as an example by pointing out how she dresses like a guy. Both ladies were not amused.
'Kung Fu Fight Club' has Shifu enthusiastically joining in the 'free fight' at the end. Po knocks Shifu down, only to be thrown over and hit in the face in response. Also, Po only recognises it's Shifu when his master removes his very obvious 'disguise' of a hat and glasses.
In Huge we have Gah-ri's talk about if Fung had a positive self image.
Peng's way of convincing General Tsin that he's crazy in Qlin. By repeatedly saying saying so.