NBC may have accounted for the top three programs on the Nielsen rating list for last week, but it was CBS that took overall ratings honors, thanks to strong performances by scripted reruns and by its formidable summer reality series Big Brother , now in its 12th season. ( Big Brother posted its best ratings since 2007 for its Wednesday installment.) Topping the Nielsen list was NBC's coverage of the Primetime Emmy Awards, which attracted 13.50 million viewers, virtually flat with last year. The Tuesday performance edition of America's Got Talent came in second with 10.80 million viewers, while the AGT results show on Wednesday attracted 10.52 million. It tied for third place with Fox's coverage of the NFL preseason game between Pittsburgh and Denver, which competed against the Emmys telecast. Among the nightly newscasts, NBC Nightly News with Brian Williams continued to lead with 7.23 million viewers. ABC World News with Diane Sawyer was not far behind with 6.60 million. But the CBS Evening News with Katie Couric tied its record-low mark of last week with 4.89 million viewers.

The top ten shows of the week according to Nielsen Research 1. Primetime Emmy Awards, NBC, 8.4/14; 2. America's Got Talent (Tuesday), NBC, 6.5/11; 3. NFL Preseason - Pittsburgh At Denver, Fox, 6.1/10; 3. (Tie) America's Got Talent (Wednesday), NBC, 6.1/10; 5. NCIS , CBS, 5.9/10; 6. 60 Minutes, CBS, 5.8/11; 7. Two and a Half Men , CBS, 5.5/9; 8. The Big Bang Theory , CBS, 5.3/8; 9. Big Brother 12 (Wednesday), CBS, 4.7/8; 10. Big Brother 12 (Thursday), CBS, 4.6/8; 10. NCIS Los Angeles , CBS, 4.6/8.