“The Tonight Show,” “Today,” “60 Minutes,” “All...

“The Tonight Show,” “Today,” “60 Minutes,” “All My Children”--when something works on television, it stays. And to those venerable small-screen institutions one must add “The Price Is Right,” the simplest of game shows and yet the longest lasting. “The Price Is Right” celebrates its 30th anniversary tonight with a one-hour prime-time edition (8 p.m., CBS), and what’s amazing about that is it’s only the 30th anniversary in this incarnation, with Bob Barker as host. The show itself dates back to 1956, when it premiered on NBC. There was also a version on ABC in the ‘60s.

Tonight’s celebration, taped in Las Vegas, is actually about seven months early in terms of the anniversary date, but there’s no reason to doubt that the show will get there. With its simple premise of having everyday people try to guess the retail value of items ranging from potato chips to new cars, “The Price Is Right” remains one of the most popular programs on daytime television (weekdays at 10 a.m., CBS), averaging 5.8 million viewers per program this season.

And Barker--a TV institution himself, having hosted “Truth or Consequences” for 18 years in addition to his stint on “The Price Is Right”--remains at 78 an affable host who still seems to get a kick out of the contestants.

And why not? They continue to go bonkers when Rod Roddy calls for them to “come on down.” You’d think they’d wait to celebrate until they actually won something, but apparently the chance to compete is thrill enough. After all, they’re on television.