Every decade or so, the country inaugurates a new civic sex symbol, some irresistible, come-hither town exalted by the listmakers and poll-takers as the most charming, beautiful, desirable place since Adam and Eve were evicted from Eden.

It`s Seattle`s turn.

Seattle is shaping up to be what Los Angeles, Houston, Phoenix and Atlanta have been in decades past-a mecca for half of everybody who`s sick of living where they live. Last fall, Money magazine rated it the most livable city in the country, ahead of San Francisco.

But if Seattle is the new sex symbol of cities, it`s the PG-13 kind. It`s a Kim Basinger stripped of lipstick and sporting an Eddie Bauer parka. It`s a Michelle Pfeiffer on a 10-speed with a good book in her knapsack. It`s a Marilyn Monroe who sips cappuccino in one of the ubiquitous downtown espresso bars while pondering the city`s new program for recycling disposable diapers. It`s also a city that thinks its fame is overrated.

In the last two years, 25,000 people have migrated to the self-proclaimed Emerald City searching for a patch of paradise and an affordable house. A legion of boomtown troubles has followed, none more infuriating to longtime locals than housing prices, which last year rose a mind-boggling 37 percent.

The rapid growth has shocked the big little town on Puget Sound, which until not long ago prided itself on being America`s best-kept secret.

To many in Seattle, this was the last good place, a politically progressive outpost that mixed natural grandeur with commercial grit, a city where skiing and sailing were ways of life, not lifestyles, where even a lumberjack could afford a house with a view of a lake, the bay or snow-capped peaks, and nobody wore ties to dinner.

''It was comfortable, complacent, insulated, a long way from anywhere,''

says Emmett Watson, 71, the crusty, white-maned columnist for the Seattle Times. ''We looked upon anybody east of the mountains as `them,` the outsiders.''

Back in the 1950s, long before very many of ''them'' had discovered the Pacific Northwest, Watson helped found Lesser Seattle, a curmudgeonly counterpoint to Greater Seattle Inc., the cheerleading club of the town`s pro- development leaders, many of them the powerful men who plotted the city`s fate over lunch at the Rainier Club.

Lesser Seattle began as a joke with a serious message. By the late 1980s, however, it had sparked a revolt, particularly against real estate-rich Californians fleeing their ravaged, overpriced state. Lesser Seattle anointed KBO agents, short for ''Keep the Bastards Out,'' and proclaimed its motto:

''Have a nice day-somewhere else.''

''We`re afraid of the `l` word, the limit word,'' laments Brewster Denny, a great-grandson of city founder Arthur Denny who advocates more restrictions on growth.

The University of Washington professor recalls how Arthur, who led an expedition of five families from Illinois in 1851, dispatched his brother, David, from Portland to scout the Seattle territory.

''Come soon,'' David reportedly wrote back. ''There is plenty of room for 1,000 settlers.''

Almost 2 million settlers later, the newcomers keep coming, and with them, change both good and bad.

In the last five years, Seattlites have watched a thicket of skyscrapers spring up along the hilly downtown horizon, among them the 76-story Columbia Seafirst Center, the West Coast`s tallest building. In that same period, the city has built a convention center, begun a new art museum and almost finished a $415 million underground bus tunnel that is as grand as a cathedral.

''Seattle is a couple of years beyond thirtysomething and ready to get to its next level of maturity,'' says Mayor Norm Rice. ''People coming here now are secure in what they want out of life. They are economically advantaged people, not just people coming in search of new jobs.''

In fact, many come without jobs at all, seduced by what Rice calls ''the spirituality of Seattle.'' D`Anne Mount was one of them.

''This place is full of new people who took huge pay cuts or jobs they`re overqualified for just because they want to live here,'' says Mount, a former Washington, D.C., resident who works for the city. ''Your priorities change in an environment like this.''

That environment includes not only the mild, if rainy, weather, but also the lakes, the sound, and the Olympic and Cascade Mountains.

The political and cultural environments lure many others as well. This is a town that, though barely 10 percent black, last year elected a black mayor, Rice. It`s a town that upon learning that $500,000 worth of South African granite was about to be installed in the new bus tunnel, banned its use.

It`s a town with a respectable symphony, one of the country`s best operas, and perhaps the most innovative theater west of Chicago. One percent of the cost of all public capital projects is used for public art.

It`s a town notorious for citizens` crusades. Last spring, one of them resulted in a 38-story limit on future downtown office buildings.

''This is a town where people believe that democracy still works,'' says Peter Steinbreuck, an architect who is leading the latest crusade, this one to save the funky, public Pike Place Market from being taken over by New Yorkers. Seattle was settled largely by Scandinavians who came to work the railroads and the lumberyards, and their influence remains strong.

Seattlites are modest, hard-working, provincial, polite and overwhelmingly white, despite growing Hispanic and Asian communities. Perhaps the worst thing you can say about them is that they are relentlessly yuppie, though they are yuppies who read and recycle.

It`s a point of civic pride that even though this was a brawling and bootlegging town in its early days, it had a university before it had a whorehouse. Even the wealthy, such as the Nordstroms of department store fame, live discreetly. Jaywalking is tantamount to murder.

As for politics, says Brewster Denny, ''they`re almost embarrassingly clean.''

Not everyone is wild about Seattle`s Scandinavian restraint.

''There is a blue-collar ethic here that is admirable to a degree,'' says Victoria James, a California immigrant who recently announced that after her rude reception she was heading back south. ''But if you`re not in your plaid shirts and hiking boots, you kind of stand out. If you`re more sophisticated, or use a lot of superlatives, or smile a lot when you talk, you stand out.

''People up here seem very comfortable with working their behinds off and having nothing to show for it. And this is not a Jaguar town. Better to buy a Bronco.''

For years, this was the city that Boeing built. In the late `60s and early `70s, when the airplane manufacturer laid off half its workers, Seattle crashed. A billboard on the outskirts of town asked that the last one leaving turn out the lights.