Nineteen years ago, TV producers Jonathan Murray and Mary-Ellis Bunim put seven ordinary 20-somethings from different backgrounds into a house and launched the phenomenon known as reality television.

On Wednesday, their show "The Real World" embarks on its 25th season on MTV with much the same format and a new set of young men and women living together under one roof in Las Vegas. But now the series is just one of several hundred reality shows a year on U.S. TV, and it faces the same dilemma people do as they age, becoming old-fashioned.

"I always had a healthy respect for real people and that they would give me more interesting stories than I could ever try to fabricate," Murray told Reuters.

"But I had no imagination in 1992 that 'The Real World' would last this long. When we first sold the idea to MTV, it was a great experiment. It was a unique idea.

"It has been able to stay fresh because it is always reflecting where young people are, and what is important to them at the time," Murray added.

In its early years, "The Real World" pushed boundaries and drew attention as the stories of its young roommates revealed the attitudes of a new generation toward race, AIDS, immigration and abortion, among numerous cultural touchstones.

It showed that regular people, without a script, could be as compelling to watch as actors or celebrities, and it paved the way for a plethora of relatively cheap-to-make competition shows, quasi documentaries and series about the lives of "housewives", socialites or couples with multiple children.

According to a recent survey by Kansas City Star TV critic Aaron Barnhart, nearly 600 reality shows aired on U.S. networks in 2010 alone.

When Andy Dehnart launched his Realityblurred.com website 10 years ago, he was able to keep track of about seven reality shows. Now some cable networks have built their entire economic structure around reality programing.

TACKY TO TREASURED

Although reality TV is often much-maligned, the genre has become a permanent fixture. "I think reality TV has developed into a mature genre that has a wide range, from total trash to incredible art," Dehnart said.

Where "The Real World" now fits into that range depends on who you ask. The 2010 season averaged 1.8 million viewers and was the 8th most popular of MTV's 30 series, MTV said.

The 25th season in Las Vegas comes with all the temptations Sin City has to offer, including a pimped-out penthouse suite in a casino hotel, a well-stocked liquor cabinet and a male gay porn star among the cast.

Murray said "Real World" is one of a few reality series that film material for 16 or 17 weeks, compared to some shows that shoot for about 12 days.

But some TV critics say "The Real World" has become increasingly superficial, and a showcase for bad behavior.

"The show ends up being, 'let's get into the house, let's get completely drunk, let's hook up with each other, let's get into fights'," said Dehnart, a former fan.

Us Weekly said the "seven sleazy insta-roomies...flash more skin than personality in the premiere (episode). Take it from the appealing 'Jersey Shore' gang: it takes more than a racy hot tub scene to entice viewers."

Some broadcasters are finding success with a more traditional, documentary feel to their reality series, such as Animal Planet's new "Taking on Tyson" about former boxer Mike Tyson's passion for pigeons, or Discovery's "Deadliest Catch" about Alaskan crab fishing, which drew a record 8.5 million viewers for a dramatic July 2010 episode.

"People are looking for things that don't feel like a TV show. Men especially like to watch things that feel real and that aren't frivolous," said Murray, about the future direction of reality TV.

But Murray hopes there are still many more years ahead for "The Real World."

"It is a wonderful show to be able to make. It is a unique time in a young person's life. As long as the audience continues to watch it, I love making it."