When it's comedy time, The Big Bang Theory rules

The Big Bang Theory is also the most popular sitcom among viewers ages 18- to 49-years-old, although the gap with Modern Family is narrower.

No one is coming close to challenging The Big Bang Theory when Americans turn on prime-time television in search of a few laughs.
The Nielsen company's ratings last week illustrate the CBS comedy's dominance. Nielsen said 15.2 million people watched The Big Bang Theory last Thursday, far above the second most-popular sitcom, ABC's Modern Family, which had 8.4 million viewers.
The Chuck Lorre-created comedy about socially challenged brainiacs is headed toward some memorable episodes, with Jim Parsons' character, Sheldon Cooper, about to consummate his romance with Amy, played by Mayim Bialik.
The Big Bang Theory is also the most popular sitcom among viewers ages 18- to 49-years-old, although the gap with Modern Family is narrower.
The bench strength for televised sitcoms has to be concerning for television executives. At NBC, ancestral home of Cheers, Friends and Seinfeld, the most-watched sitcom last week was Undateable, a Friday-night show with 2.7 million viewers. Jimmy Fallon often draws that many viewers late at night.