From the AP

The CBS drama ``CSI: Crime Scene Investigation'' is officially the nation's favorite program, while CBS is once again the most popular network.

Wednesday's end of the television season, which coincides with the start of a frantic ad-buying period, also provoked an unusual argument about profitability among top CBS and NBC executives.

CBS averaged 12.5 million viewers in prime-time this season, up 2 percent from last year, according to Nielsen Media Research ratings through Sunday. NBC was second with 11.7 million, a 14 percent drop, although roughly half of that decline can be attributed to NBC broadcasting the Winter Olympics in 2002 and not this year.

ABC was third with 10 million and Fox fourth with 9.8 million, both increases. ABC may have avoided fourth place simply by broadcasting the Super Bowl and Academy Awards.

It was the first season ``CSI,'' a drama about solving creepy crimes, has been the nation's most popular show. Its average of 26.2 million viewers each week easily beat second-place ``Joe Millionaire'' of Fox, which had 22.9 million in a limited run. NBC's ``Friends,'' last season's top show, was third with 21.8 million viewers, Nielsen said.

Five of TV's 10 most popular shows were reality, including two ``Survivor'' games and ``American Idol,'' whose two separate editions each week are counted as separate programs by Nielsen.

The three most popular scripted series this season - ``CSI,'' ``Friends'' and ``ER,'' - were the three most popular last season, too.

Far from congratulating CBS, its three rivals barely even recognized the accomplishment. That's because NBC, ABC and Fox all pay closer attention to the 18-to-49-year-old demographic favored by advertisers - essentially not caring if anyone over age 50 is watching.

In that demographic, NBC reigned supreme for the seventh time in eight years, although the race tightened. Fox, CBS and ABC followed in that order.

The argument was sparked by CBS chief executive Leslie Moonves' statement that he believes CBS is the most profitable network in prime-time. He said CBS' Thursday lineup, with ``Survivor'' and ``CSI,'' is the most profitable night in TV - ending a stranglehold NBC had on that night for 18 years.

But NBC entertainment president Jeff Zucker called Moonves' claim ``laughable'' and suggested his CBS rival be hooked up to a lie detector test.

``Remember, just because Les says something doesn't mean that it's true,'' Zucker said. ``Let me assure you that NBC's prime-time schedule is far more profitable than anyone's.''

Zucker said the advertisers that NBC deals with care exclusively about the 18-to-49 age demographic. Over the next week or so, advertisers are expected to buy some $8 billion in commercial time on the broadcast networks for next season.

``They say the only thing that matters is the 18-to-49 demographic because that's the only place that money is coming into,'' Moonves said. ``Well, the money's coming in here just fine.''

Perhaps the happiest network this week is Fox. With an expected big rating from the ``American Idol'' finale on Wednesday, Fox will win its second straight ``sweeps'' month in the 18-to-49-year-old demographic - for the first time ever. Ratings are watched closely during sweeps to set ad rates.

``This truly has been the most memorable and successful season in Fox history,'' said Gail Berman, Fox entertainment president.

Among all viewers, CBS won the May sweeps.

Among the smaller weblets, the WB leapfrogged over UPN this season for fifth place, up 9 percent over 2001-02. UPN saw an 18 percent drop in viewership, renewing questions about its long-term viability