The San Francisco 49ers and Seattle Seahawks are two powerful football teams that represent glittery cities crazy about high-end coffee, West Coast cuisine and high-tech.

So what's all the hate about?

The growing football rivalry between the two teams and their fans has developed into one of the fiercest in the NFL. The nasty pregame chatter leading up to Sunday's NFC Championship game is lighting up West Coast sports radio. Seahawk fans have prevented Californians from landing seats at the game, while other Seattleites have tried to purchase "Go 'Hawks" bricks in the Niners' new Santa Clara stadium.

Jorge Lee, a Sausalito entrepreneur, has started a T-shirt company that takes a shot at Seattle's 12th Man, the nickname for its raucous fan base. The shirts simply state: "12 Men. 0 Rings."

Ouch.

"These teams don't hide that they really hate each other," said Ken Sapp, a bartender at Britannia Arms, a sports bar in downtown San Jose. But though the gridiron-based enmity is real, much of the howling and growling is fired by other competitive reasons.

"Who's got the best coffee? Who has the finest restaurants?" asked Jeffrey Holifield, a San Jose fan who loves the Seahawks because he grew up in Seattle. "Whose city is prettier? More cosmopolitan? Which place gets more cool points?"

For everyone who defends San Francisco looking down its Coit Tower nose at Seattle for being smaller, colder and wetter, there are Space Needle-loving Seattle residents declaring their urbane burg as friendlier and cleaner, sans insane traffic and battalions of aggressive panhandlers.

Cable cars vs. monorail. Fisherman's Wharf vs. Pike Place Market. San Francisco Bay vs. Puget Sound. Apple vs. Microsoft. And on it goes, with both never shutting up about how "beautiful" they are.

Nelson Estupin, a die-hard Niner fan from San Jose, believes that all the competition on and off the field breeds a growing regional contempt that will fester for years to come.

"Both feature great culture and night life," said Estupin, who works at the Santa Clara County Office of Education. "Both consider themselves high-tech giants, and both are famously passionate about their teams. They have the loud and proud 12th man, but no championships. We have fan roots, going back to the '80s, that are planted in the rich soil of five Super Bowl titles."

The uncivil war begins with the coaches. San Francisco's Jim Harbaugh and Seattle's Pete Carroll launched their hate affair as North-South competitors -- at Stanford and USC -- and things got more malevolent after they both landed in the NFC West.

"Seahawk fans absolutely haaaate Harbaugh," said Holifield, a high-tech attorney who will fly up to Seattle on Sunday to join his 'Hawk-loving family at CenturyLink Field. "They haaaate watching Harbaugh on the sideline, scowling, gesticulating and bitching."

While Holifield's wife, Michele, a bleeding-heart Niners fan, will barely tolerate watching the game with her turncoat husband, she reports that "people down here haaaate Pete Carroll, smiling, chomping on that wad of gum, running up and down the sideline."

Footballwise, the head-butting is intensified by two young, handsome, highly mobile quarterbacks. Both Colin Kaepernick and Russell Wilson are overachieving rock stars who angrily endured being afterthought draft selections.

On defense, both feature bullying brutes. And on offense, the Niners' Frank Gore and the Seahawks' Marshawn Lynch are a couple of tireless pigskin toters.

Finally, both teams offer unapologetic trash-talkers -- the 'Hawks Richard Sherman and Golden Tate vs. the Niners' Anquan Boldin and Donte Whitner. All are highly annoying gumslingers who back up their boasting on the field.

"This game will be Ali-Frazier type stuff," said Sean Babani, a bartender at Rookies Sports Bar in Seattle. "Now the fans will get exactly what they want from teams that play football the way it was meant to be played."

A final aspect of the rivalry has to do with canine psychology. For many years, the Niners ruled the NFC West before fading into irrelevancy. Seattle became the new dog, but just as that franchise is about to land its first ultimate prize, "the old dog is back and is as mean and ugly as ever," Estupin explained. "Niner fans are anxious to be winners again while Seahawk fans are like, 'Wait, this is still our party!' "

Jason Puckett, a Seattle sports-talk host, says most of the pregame talk he hears is full of passion, laced with great anxiety. For Seattle to face such a formidable blockade to their dreams is frightening. But those fans are smitten by the "un-Seattle-like" personality of a team that this year is confident and badass.

"There is a controlled craziness to our team that deeply pleases fans up here," said Puckett, of KJR 950. And those emotions carry over to Carroll. "No one on that team has more moxie than Pete," Puckett said. "He struts through that locker room with so much positive energy that players and fans gravitate to him."

Back in the Bay Area, Niner fans say they can't wait to see Carroll's strut turn into a stumble.