The song Hare Hare Yukai on which Haruhi, Yuki and Mikuru performed on the ending of Melancholy of Haruhi Suzumiya (which can be viewed below) spawned a multitude of parodies. Here is a compilation of the best Hare Hare Yukai parodies (which can be seen after the jump).
Super Smashed Bros version
Phoenix Wright version
Lucky Star version
CPDRC inmates version (OUR VERY OWN!)
Live action version (featuring the seiyuus of the anime version)