Sitcoms generally have a short shelf life. "The Big Bang Theory" is a notable exception. Millions of people, myself included, have reveled in its offbeat humor & brilliant writing for more than a decade. That being said, they've decided to call it a day. Jim Parsons (Sheldon) is reportedly the one who decided the time has come. "That 70's Show" hung around for one season too many after the departure of 2 central characters. "Two and a Half Men" hung on for three seasons too many after the bitter split between producer Chuck Lorre & bad boy Charlie Sheen. Lorre also produces "Big Bang." How do cast members feel the show should end?...