• by Wayne Friedman , October 1, 2010

With the exception of Univision and CW, all broadcast networks dropped anywhere from 8% to 18% in ratings from last week's big Thursday premieres.

CBS still came out on top among 18-49 viewers with a Nielsen preliminary 3.3 rating/9 share (down 11%); ABC, was next with a 2.8/8 (18% lower); NBC dropped to a 2.3/7, off 12%. Fox lost the least of the four major networks, at 8%, to a 2.2/6. Univision stayed the same with a 1.7/5 and CW was even with a week ago, a 1.3/4.

CBS' installation of "Big Bang Theory" has, over its first two weeks, proven to be the right move. The network has topped ABC, which led the way on Thursday night for virtually the entire season last year.

ABC's "Grey's Anatomy" is still the best-rated show of the night, with a 4.5 rating/12 share among 18-49 viewers, but "Bang" is closing in, earning a 4.3/12. "Grey" dropped eight-tenths of a rating from a week ago; "Bang" lost about five-tenths of a rating point.

Other big shows' ratings lost ground: NBC's "The Office" came in at a 3.7 rating from a 4.3 the week before; CBS' "CSI" dipped to a 3.0 from a 3.4 in the premiere week; CBS' The Mentalist" dropped to a 3.0 from a 3.3; ABC's "Private Practice" sank to a 2.9 from a 3.3; and Fox's "Bones" went to a 2.5 from a 2.7.

New shows were not immune to hits: "$#*! My Dad Says" dropped 20% lower to a 3.2/10; "Outsourced" sank about the same, 22% to a 2.8/7; and ABC's "My Generation" gave up 27% to a land at a dismal 1.1/4.

NBC stayed the same with two shows: "30 Rock" at a 2.6/8 and "The Apprentice" at a 1.4/4.

CW maintained good results for its 8 p.m. "Vampire Dairies" among its key women 18-34 viewers, just losing one-tenth of rating point to a 2.5 rating. (It also earned a 1.8/6 for all 18-34 viewers.). But "Nikita," the network's new 9 p.m. show, still suffers in this area, down 15% to a 1.1 rating among 18-34 women and a 1.0/3 for overall 18-34 viewers.