One of our 100 darkest moments in pop culture history series. Michael Richards played the quirky character Cosmo Kramer on the popular Seinfeld television sit-com. Kramer was a fan favorite character eliciting cheers every time he popped in the door. After Seinfeld ended its run, while still an incredibly popular show, Michael Richards took a try at standup comedy... then it went wrong. Very... very... wrong.