Now that the character is regarded as one of his career-defining roles, it's hard to imagine anyone other than Jim Parsons playing Sheldon Cooper on "The Big Bang Theory." After all, the actor ...

Nearly two decades ago, The Big Bang Theory retconned a major element that saved it from an issue that coule have ended the series.

Sheldon Cooper (Jim Parsons) is the heart and soul of "The Big Bang Theory" — for worse or for better, depending on how you feel about the sometimes controversial, sometimes abrasive character.