When the gang discovers a creature in their hangout in "How To Rock A Messy Bet":
Kacey: Cat! Stevie: That was not a cat! Nelson: I think it ate the cat!
The exploding chocolate fountain in How To Rock A Guest List
Kacey acting like she's close with Big Time Rush even though she's only connected to them through a very minor, six degrees of separation type relationship.
The end of "How To Rock a Lunch Table": Kacey and Stevie hung a bird feeder over the Perfs table so that the birds would go there and poop on The Perfs instead. It works.
Grace's attempts at sarcasm in "How To Rock A Lunch Table".
Kacey and Nelson simulating an argument between Kacey and her mother in "How To Rock A Part-Time Job." It Makes Sense in Context...kind of.
Kacey in a giant mango costume.
In one scene in "How To Rock A Basketball Team", Nelson, Zander, and Kevin are sitting on the Gravity Five couch, which has somehow found it's way into the bleacher's in the gym. During a timeout, Stevie walks over to them and asks how they got the couch into the gym. Nelson looks up and asks "We're in the gym?"
Nelson and Kevin freaking out about not being on the same team in "How to Rock Camping"