Neverending Television

ER, 1994
For twenty years, Jurassic Park author Michael Crichton had a script sitting around based on his experiences as a Boston medical student. Following the success of Steven Spielberg's 1993 version of his dino-thriller, Crichton and Spielberg brought ER to NBC. It was an immediate hit: the goings-on at Chicago's County General Hospital have become the Tyrannosaurus Rex of TV medical dramas for 15 seasons, launching the career of George Clooney along the way. As of April 2, 2009, however, ER too had become extinct.

• ER's Long Goodbye