WHAT IS THE MOST UNIQUE SONG THAT YOU HAVE EVER HEARD?

Timothy - The Buoys. Although there may have been other songs about cannibalism, I don't believe any other one made it to the top 20 on Billboard as did Timothy. Trivia note: It was written by Rupert Holmes, famous for Escape (The Piña Colada Song) and he played piano on Timothy.
Honorable mention: Can't believe no one mentioned Bohemian Rhapsody by Queen. Very unique in its day and made it into the top 10 twice in two different decades.

Time to flex...

+1 for Friends of Mr. Cairo, Jon and Vangelis. I love the ending when the audio dies and the film flops off the reel.
Tori Amos, Icicle.
Klaatu, Calling Occupants of Interplanetary Craft

A Day in the Life


2112


+1 on Calling Occupants (Klaatu version)

There are so many unusual songs by They Might Be Giants:
Particle Man
Birdhouse In Your Soul 
Istanbul 
Boss of Me (the theme song to "Malcolm in the Middle")