New York ? Who needs highly paid actors? A hunky construction worker, a love-starved former cheerleader and a hymn-singing teenager became stars in a landmark week for reality television.

Fox’s “Joe Millionaire,” ABC’s “The Bachelorette” and CBS’ “Star Search” all impressed television executives with their ratings performances last week.

And the mood at the WB “approached a level of giddiness” over the ratings for new shows “High School Reunion” and “Surreal Life,” said the network’s entertainment president, Jordan Levin.

After years of searching for an alternative to sitcoms and dramas, last week’s results proved that reality shows have become a powerful new genre.

“It was time for a new idea, and this is it,” said Robert Thompson, professor of media and popular culture at Syracuse University.

Meanwhile, interest in scripted fare is fading. Of the 20 most popular comedies or dramas last season, only three — “CSI: Crime Scene Investigation,” “Will & Grace” and “The Simpsons” — have a larger audience this season than last. “NYPD Blue” is about even.

“Joe Millionaire” was most impressive in reality-show ratings. The cruel parody — in which eligible women woo a construction worker who they mistakenly believe is a millionaire — drew 18.6 million viewers to its premiere.

Many wanted a second date: Monday night’s second episode was seen by 17.5 million, Nielsen Media Research said Tuesday.

Hit-starved ABC struck gold with “The Bachelorette,” which offered former cheerleader Trista Rehn her choice of eligible men. Its audience of 17.4 million beat NBC’s competing drama, “The West Wing,” by nearly 4 million viewers.

In a nod to Fox’s soon-to-return “American Idol,” CBS resurrected “Star Search” for two episodes last week. Both landed among Nielsen’s top 30 prime-time shows. Big-voiced 13-year-old Meaghan Markert impressed the judges with her rendition of “Ave Maria.”

The WB’s “High School Reunion” follows a real-life high school class playing out personal dramas 10 years after graduation, while “Surreal Life” takes fading stars like rapper Hammer and puts them in the same house.

Evan Marriott plays Joe

“The ratings are high because it’s stupid and moronic,” Thompson said. “That’s part of the fun of the whole thing. After 20 years of the age of irony, why would it be surprising that a whole genre would arrive that we can both disdain and enjoy at the same time?”

The shows also succeed because they play off situations — looking for love or wondering what happened to a high school friend — that everyone can relate to, he said.

As such shows proliferate, their grip on “reality” becomes more tenuous.

It was a big story three years ago when Fox’s “Who Wants to Marry a Millionaire” turned into a farce. But when unsavory stories came out about “Joe Millionaire” Evan Marriott — his past work modeling skimpy underwear, for instance — the public seemed to shrug.

“Not only do they not care, they expect that,” Thompson said.

CBS President Leslie Moonves said he’s trying to figure out the limits to the public’s taste for these shows.

His network’s plans to revive “The Beverly Hillbillies” with a real-life family have run into protests from a group representing rural Americans, and Moonves said he’s not sure the network will go through with it.

“Everybody’s looking for that quick fix,” he said. CBS is even looking for its own version of a dating show.

Reality shows aren’t appealing to networks in the long term because they don’t form lasting relationships with viewers the way a scripted show can, Levin said.

“I think you have to be very careful with reality programming because it can be very seductive, but it can start to force you into a place where you’re juggling your schedule to satisfy a very short-term fix,” he said.