Adaptation Displacement - The animated series is far more widely known in the West than the manga it's based off. Increasingly not the case with time, though, as a full 10 volumes of the ongoing manga have been released in English, keeping it in the public eye much longer than the one-and-done anime (and also covering about four times as much material).
Big-Lipped Alligator Moment: Episode 17 starts off with Tsuruya using some kind of wind magic. While other episodes show her fighting beyond human limits, she never uses this particular power again.
Yuki's bunny headphones have become synonymous with her Haruhi-chan incarnation.
Suspiciously Similar Song - The theme for the Dating Sim intro sound like the Nursery Rhyme intro "True My Heart". An especially generic example, since "True My Heart" is already memetically generic.
When Kyon's little sister kicks Kyon upon his opening the front door in the first episode, she says death instead of desu (they're both pronounced "dess" in Japanese). This joke makes zero sense in English, so the subs give her the vaguely threatening "Nice to see you alive, Kyon!" In the dub, she says "Welcome Back Attack" in which Kyon says that she changed a simple greeting into an attack.
Part of Episode 2 has the characters participate in a fire evacuation drill, with the joke being that Churuya was unable to escape. This would be harder to laugh at in light of the arson that happened at Kyoto Animation (who made the animated adaptation of the Haruhi Suzumiya series) on July 2019, which killed several of their staff members.
plays during the dodgeball match.
