If you’re an otaku, or even a real anime fan, you certainly already heard of Suzumiya Haruhi no Yuutsu.
And if you already heard of Suzumiya, you probably also know about it’s trademark dance: Hare Hare Yukai

If you don’t, this is a wordwide famous otaku dance that received tons of official and fanmade versions mixing with other stuff, with live people, other types of animation, etc etc.
This post has a collection of Hare Hare Yukai versions!
(WARNING: Tons of YouTube videos ahead!)

Since there’s not much to add about them, here they go:

Suzumiya Haruhi no Tomadoi (Playstation 2 official 3D Haruhi Game)

Suzumiya Haruhi no Gekisou (live show with Suzumiya seyuus)

Lucky Star tribute to Hare Hare Yukai

Nendoroid Haruhi characters

Complete with Studio “Making of”

Hatsune Miku 3D

Pika Pika Yukai (Hare Hare Yukai with Pokemons)

Megaman/Rockman

Megaman/Rockman Comparison with the original

5 Styles Comparison (Gekisou, TV, Lucky Star, Tomadoi, DVD)

9 Styles Comparison

CPDRC inmates (the folks from the Phillipines Prison Dance)

Black Tie?

Shiraishi Minoru Live

Tales of Hare Hare Yukai (characters from the “Tales of…” series)

Miku Miku Dance

Chibi Miku Miku Dance

iDOLM@STER

Busou Shinki Figures

Kyonko

Genderbent

Animal Crossing – KK Slider

Spoo/Supu 3D! o_O

WTF?

Neon Genesis Evangelion 3D

…and there’s also the 8bit version and Montage at Akihabara I posted sometime ago!

And now you’re completely tired of hearing and watching Hare Hare Yukai.