Seinfeld was a television show.
Cosmo Kramer , usually referred to as simply `` Kramer '' , is a fictional character on the American television sitcom Seinfeld ( 1989 -- 1998 ) , played by Michael Richards . Nielsen ratings are the audience measurement systems developed by Robert F. Elder and Louis F. Woodruff and sold to Nielsen Company , in an effort to determine the audience size and composition of television programming in the United States . Seinfeld . It has been ranked among the best television shows of all time in publications such as Entertainment Weekly , Rolling Stone , and TV Guide .