These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: The Emperors New School
Nightmare Fuel: Show of hands, who wasn't freaked out by the skeleton ant eater? On the bright side it came with a really catchy song.
Seinfeld Is Unfunny: The series reused so many jokes from the movie so many times that they became more annoying than funny.
This is Lampshaded in one episode in which the whole "Roller Coaster Inside The Lab" joke was used so many times that it actually couldn't come up with something witty to say that hadn't been said before.
Another Lampshade Hanging comes when Yzma struggles to think of something new to turn Kuzco into and suggests a llama. Kronk asks, "You're kidding, right?"
Yet another Lampshade Hanging in that episode comes when Yzma tells Kronk to pull the lever, and Kronk does, causing something they've seen before to come down. He then keeps pulling the lever saying "Seen that, seen that" until they flip in. If I remember correctly that was basically a whole Lampshade Hanging episode about Kronk feeling like they're in a rut.
This is more of an It's Been Done thing if anything but how do they keep things so fresh and funny anymore.