There's several fun moments in the first full moon episode, especially the part where Emma uses her powers to freeze Zane and Miriam's lips together.
Emma's line to her aunt "Aunt Thea, your skirt...did you steal our picnic rug?"
The entire episode is a nice Parental Bonus because of how similar it is to a teenager getting drunk for the first time at a family party.
This exchange between Lewis and Rikki was quite amusing:
Lewis: I have made an amazing discovery! Rikki: You're an android!
When Emma is getting stressed about organizing her father's birthday party...
Rikki: You're grinding your teeth.
Emma: It's called a smile, Rikki.
Earlier on, Emma snaps at her brother for decorating the house with black balloons. As soon as Rikki and Cleo arrive, Rikki takes one look at the balloons and says "welcome to my Gothic world"
"The Big Chill" is full of them, particularly thanks to Emma's Control Freak and zany behavior.
Emma: You're six minutes and ten seconds late!
Rikki: Should I go stand in the naughty corner?
When Rikki quits her job out of frustration, Emma runs after her saying "you can't just quit. You have to fill out a resignation form!"
When they're trying to deal with a frozen Miriam...
Lewis: Rikki will use her powers to try and warm the body—
Emma: Don't call her that!
When Miriam gets revived, Emma rushes forward and hugs her frantically while Miriam hasn't got a clue what's going on.
The end of the episode has Wilfred noting that Rikki is doing quite well in her job, while he's very disappointed with how Emma behaved. Rikki decides to throw her job and immediately yells at a customer to drink her juice faster. What's funny is that the customer actually does.
Kim gets a lovely Be Careful What You Wish For moment in the wish granting episode. Cleo is in the bath and Kim is ranting to her father "I just wish I could have a shower when I wanted one!". This activates Cleo's wish-granting powers (she's in mermaid form) and Kim gets showered with the garden sprinkler.
Most kids trying to fake being sick to get the day off school would pretend to cough or sneeze. What does Cleo do in "Under The Weather"? She pretends to faint.
Moments later when the girls are asking her what the plan is, she says "I'm making this up as I go along" - in the most proud and ditzy tone of voice ever.
The entire house gets quarantined because Dr Holt thinks the girls have some rare tropical illness. The specialist comes back with test results and the girls are all cleared as healthy - except for Elliott, who's got the measles. The reactions of Dr Holt and the team she called in are priceless.
Kim getting her comeuppance at the end. She discovers she accidentally caught the measles off Elliott (by drinking his water).
In "The Sorcerer's Apprentice", after her goldfish ends up in a floating ball of magic water, Cleo walks up and, in a forlorn voice, says, "Hector?"