The first time I'd ever watched a Cirque Du Soleil show was actually on a 3D screen, Journey of Man. I personally didn't like the film as a whole, but the acrobatics really got me hooked.
My favourite part was the scene with the two statues. How anyone was able to hold those positions for any length of time astounds me to no end. Yes the picture on the left are two human beings, and not inanimate object, and yes, they are holding themselves up using strength alone.
Since then, I've seen four Cirque Du Soleil shows: "O", Mystere, Alegria and Saltimbanco. "O" is my favourite out of the four. This one's a little different from the rest of the Cirque shows as about 2/3 of the show is done in water. I would pay money to go see this show again, and this show is not cheap to watch! Alegria is the favourite out of the tent shows.
I was poking around YouTube and found a few clips that were interesting (clips may take a minute to load):
Clip from Alegria (this is long):
Cirque du Soleil at the 2002 Oscars: