Two guys running around a cage with no walls while it spins very fast
A couple of Fridays ago, I saw Le Grande Cirque at the Concert Hall in Opera House. It was the most amazing and dangerous show I have ever seen. Similar to the circus shows out there that don't use animals, it consisted mainly of acrobats and contortionists.
The ticket sellers classified the show as a family event for children but it was lots of fun for the many adults who used their children as an excuse to go. There was plenty of audience participation with the ring master (of sorts) stealing an audience members wife, crowd surfing giant beach balls and a dance off.
One tip - avoid the glasses of champagne before hand because they can cause a little extra freak-out when elastic people are flying around the stage with flashing lights. Otherwise, it is a fantastic event for all.
Mothers don't let your babies grow up to be acrobats. I wanted to join a circus as an acrobat when I was a little girl but I take that all back. Give me a safe ground-level job and let me walk stiffly to my seat and watch much braver and more talented people entertain so thoroughly.