Haruhi-chan/YMMV

Adaptation Displacement - The animated series is far more widely known in the West than the manga it's based off.
And the Fandom Rejoiced - Chibi-fied Haruhi? Check. New, wacky adventures just before season 2? Check. More screentime for Tsuruya and Taniguchi? Check. Fanon Shout Outs? Check.
Big Lipped Alligator Moment - The beginning of episode 17.
Crazy Awesome - Yuki and Tsuruya.
Crowning Music of Awesome
- This plays during the dodgeball match.
- Myaa, Myaa, Myanko-logy de Jinrui mya?
Ensemble Darkhorse - Achakura and Kimidori.
- The famous Mikuru sheep from episode 1.
Memetic Mutation
- "You made Mikuru cry!"
- Honya~!
Memetic Outfit - Yuki's bunny headphones have become synonymous with her Haruhi-chan incarnation.
Tear Jerker - Episode 24 subverts this when it turned out Achakura and Kimidori were just goofing around.
The Woobie - Ryoko Achakura.
Woolseyism - 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. It works.

Memetic Mutation
- What caused the series to be made.
- And of course, Nyroro~n.
Most Wonderful Sound - "Nyoro~n..."
The Woobie - Churuya and Ashakura.