The news that The Simpsons has been renewed for a 15th and 16th season, making it TV's longest-running sitcom, was greeted with joy at my house, where it is woven into the very fabric of our daily lives.

We "HA-ha" like Nelson and "Mmnnmmhh" like Marge.On every road trip we take, we holler like Homer, "Be quiet, I can't hear myself think!" and then we smile, because we remember that when silence fell in Homer's car, the voice in his head became audible: "I want some peanuts," it said. "Ah, that's better," Homer sighed.

The Simpsons are better, in every way. The show celebrates its 300th episode on Feb. 16. The previous record holder for TV sitcom longevity was the Ozzie and Harriet show,and Homer and Co. have been castigated as murderers of the values for which Ozzie's clan stood. Bunkum. The Simpsons' values are stern and immutable: They celebrate humour, irony and self-deprecation, and despise self-righteousness, snobbery and hypocrisy.

Under the slapstick and yellow skin, The Simpsons' writers are America's most consistently scathing social critics. Every week, they tear down corrupt politicians, policemen and nuclear-regulatory officials, lazy teachers and incompetent doctors. They send up rampant consumerism ("Don't be fooled into buying the new Malibu Stacey!" Lisa cries to a horde of slavering shoppers. "She's exactly the same as the old Stacey." "But she has a new hat," whines Stacey-phile Smithers), self-pitying self-help lingo, and ethnocentrism (Bart, amazed to learn there is a southern hemisphere, makes crank phone calls to Burkina Faso. "What's with this crazy hemisphere?" he asks).

They gleefully point out religious fanaticism, peppy violence and substance abuse ("To alcohol," Homer toasts, "the cause of -- and solution to -- all life's problems").

The secret door to the roof garden above Apu's Kwik-E-Mart is behind the non-alcoholic beer refrigerator. "But what if someone wants a non-alcoholic beer?" Lisa asks.

"You know," Apu replies thoughtfully, "it's never come up."

That's pretty heady stuff for Comedy Central reruns. It's also flat-out amazing that the show has thrived by getting smarter and smarter on a medium -- and in a culture -- that seems to get stupider every year. The Simpsons isn't really a sitcom at all; it's the world's longest-running stealth art project. It achieves a mix of high and low humour, pop culture and art culture that museums around the world have struggled to emulate.

Simpsons'episodes nod to Kraftwerk, The Lord of the Flies,a so-called sacrilegious painting that caused a storm at a New York museum a few years ago ("I will not make art out of dung," Bart writes on the blackboard in the episode's opening credits), Edgar Allan Poe, jazz saxophonists, psychedelic drugs, General Patton and existentialism (the Simpsons rush to their couch to find themselves . . . already sitting on the couch).

The show steals from films great (Citizen Kane, 2001: A Space Odyssey, North by Northwest)and cheesy (Porky's,horror films, beach movies), comic books, vaudeville and, especially, other TV shows (Krusty the Clown's special nailed Carson's farewell episode to the wall). Many of those references are obvious. But when Bart goes to France on a student exchange, and for a half-second travels the countryside, I had to rewind my VCR twice to catch that he passes through van Gogh's Crows over the Wheatfield,Rousseau's The Dream,and Manet's Déjeuner sur l'herbe.

In fact, I credit The Simpsons with teaching my kids invaluable life lessons about exasperation, irony, off-kilter storytelling and the rewards of making even the most peripheral character wonderfully specific. Marge's unmarried sisters Patty and Selma chain smoke, take eight carousels of slides on their one-week vacation, work at the Department of Motor Vehicles and think MacGyver is the perfect man. Most characters in major movies aren't drawn half so well.

The Simpsons have also, I think, taught our kids to be funnier. The family sitcoms we grew up on were painfully bland. From Father Knows Best to The Brady Bunch,they depicted a world in which everything was orderly, and minor rifts in that order were fixed by benevolent patriarchs. That's not the world we live in. In Springfield, the youngsters are the wise ones, and their kiddie fans love it.

They also know life is not dire; they've learned how to laugh at it. Kids raised on The Simpsons -- as a couple generations now have been -- get jokes that would have gone way over my head, such as when Lisa complains to the school cafeteria cook, "The state requires you to provide a vegetarian alternative."

"There!" the cook rasps, slapping an empty hot dog bun on Lisa's plate. "It's full of bunly goodness."

Or when the creator of Malibu Stacey (voiced by Kathleen Turner) sees her ex-boyfriend, a G.I. called, of course, Joe. "Stacey, I must have you back," he says. "No, Joe!" she cries. "Release me from your kung fu grip."

Or (our favourite), when Bart dates the slyly evil minister's daughter. "You're bad, Bart Simpson," she coos.

He stammers, "No, really, I -- " until she cuts him off with, "I like bad." His voice deepens, he cocks one yellow hip. "I'm bad to the bone, baby," he intones.

The Simpsons knows when to pull back from a joke, and when to push one beyond its limit. "D'oh!" Homer exclaims after being arrested. "That's what they all say," Wiggam replies. Pause. "They all say 'D'Oh'." When Homer falls down a gorge, he hits every rock, branch, outcropping, boulder, and on and on and on. And on. And on. Finally a helicopter arrives and Homer is lifted from the gorge bottom into the sky -- only to be dropped immediately, and land on every rock, branch, outcropping, boulder, and on and on again.

Shows also switch gears in mid-episode, often more than once. You settle in to watch a story about mock-rockers Spinal Tap playing a concert in Springfield, but after one short scene, in which the concert flames out spectacularly in its first minute -- then another short scene with the band members on their bus ("Good show," David St. Hubbins says. "Yeah, quite good," Nigel Tufnel answers) -- the bus careens over a cliff, Spinal Tap die, and the episode is suddenly about Otto the school bus driver. And that part is funny, too. "Now they're saying I can't drive just because I never got a licence," Otto moans. " 'The man' says I need a piece of paper."

The Simpsons makes us happy. Before every party my family throws, one of us quotes Homer's line from an episode where Lisa tries to convince her family that they can have a barbecue without meat: "Lisa, you can't make friends with salad." Bart jumps in, chanting, "You can't make friends with salad," Homer falls into a conga line behind him, and they circle the living room singing, "You can't make friends with sal-ad! You can't make friends with sal-ad!" until even Marge joins in.

"Mom!" Lisa protests.

"I got caught up in the rhythm," Marge says, shrugging.

She can't help herself. Neither can we.