I finally made it to the Cai Guo-Qiang : I Want to Believe exhibit at the Guggenheim and I was pretty blown away. The sculptures, including the incredible row of wolves charging a transparent wall (Head On), the spiral of automobiles spraying off light tubes (Inopportune: Stage One), and the both beautiful and painful tigers pierced by hundreds of arrows, are really phenomenal and wonderful to see in person. You've probably seen plenty of photographs of these pieces, but seeing in person is another story.
What is not documented as much in articles on the exhibit are the gun powder paintings and the Explosion Events. Be sure to watch all the videos about these strange and innovative works. My favorite was the Black Rainbow project for Valencia: A daytime fireworks display of and arch of black explosions. So cool!
I recommend listening to the audio tour and going to the smaller exhibit in the basement called Everything is Museum which invites artists and children to reinvent the idea of “museums”. This must see show is up until May 28th.