Glurge: Probably the biggest example out of a SpongeBob episode. The episode seems to want to teach An Aesop about how betraying your friends is wrong, but this is undermined by multiple factors:
Given that SpongeBob is breaking the trust of an inanimate object that can't even speak, this comes across as a case of being a Clueless Aesop.
This episode borders on being a Space Whale Aesop for having SpongeBob learn a moral through extremely unrealistic methods, the most notable being Le Spatula running away and punching him in the face.
What is presumably SpongeBob's subconscious stating, "All that glittersis not gold," is a complete Broken Aesop, given that it has nothing to do with what the progression of the episode sets out to do.
Informed Wrongness: SpongeBob buying Le Spatula is meant to be seen as a betrayal, but he clearly had no choice because he needed something for work. It doesn't help that he was legitimately hesitant in buying it, but was forced to.
Wangst: SpongeBob's crying in several scenes (particularly at the beginning) in the episode has greatly annoyed some fans.
Just Here for Godzilla: This episode is generally why fans look up this pair of episodes, as it's generally considered up to the bar set by the first three seasons.
Memetic Mutation: The "claustrophobic means afraid of Santa Claus" dialogue is often requoted to make fun of certain people or groups. Usually in this format:
Squidward: I'm X.
Patrick: What does X mean?
SpongeBob: It means he's afraid of Y.
Squidward: No it doesn't!
Patrick: [Mockingly says something related to Y]
SpongeBob: Stop it, Patrick! You're scaring him!
Woolseyism: In the German dub, SpongeBob says "claustrophobic" means Squidward is afraid of "people named Klaus" instead of "Santa Claus". Patrick then teases Squidward by going "Klaus, Klaus, Klaus." instead of "Ho, Ho, Ho."