Cirque du Soleil pretty much redefine amazing. Most people would be lucky to move that way in dreams. After a while, you start to forget that it's not impossible to fly, flip, balance, and contort, it's just really really difficult and requires an insane amount of strength and training and mechanics. Physics rarely looks so nice. I think the most incredible act was the kids skipping rope, which I could not possibly explain in a way that would do justice to the performers. 1
The "clowns" ... not so much.
--- (1) Despite that praise, I have issues with people who feel obligated to give a standing ovation. It should be immediate or not at all.