Thus far, I've gotten to see O, Mystere, Ka, and Zumanity in Las Vegas, La Nouba in Orlando, Dralion and Ovo touring here in DC, and Kooza in Seattle (thanks, dragojustine !). They're all awesome, in totally different ways. Each show shares many of the same elements, but each has their own unique blend and style. The costuming of Ovo was especially awesome, as Ovo is the bug-themed show. The performers were costumed in brilliant colors as grasshoppers, dragonflies, spiders, and even cockroaches (which is a pretty cool trick, making cockroaches look cool!).
If anyone is considering catching the show while it's in DC (or nearby, anyway), I heartily recommend it - it's beautiful, and funny, and awe-inspiring.