More fashion labels have disappeared than airlines. But one has managed to stay hip for more than three decades and has evolved from being a designer-jean wholesaler to a one-stop shop for fashionistas.

In an industry where tastes change from season to season and vary on a regional basis, it’s been a challenge for Guess? (NYSE: GES) to remain relevant.

But the fashion retailer has proved itself equal to the task, and not because of its racy advertising—though that probably hasn’t hurt.

Over the past three decades the Marciano brothers—Maurice is Chairman of the Board and Paul is CEO—have stayed ahead of the fashion trends and morphed their business from a designer-jean wholesaler into a purveyor of almost every conceivable form of apparel.

And rather than strictly catering to the young and hip set—which its flagship Guess? brand clearly  does—it’s reached out to older consumers with its Guess? by Marciano line and younger, price-conscious buyers with its G by Guess? brand.

Although that broad commercial appeal didn’t fully protect sales during the height of the recession—US same-store sales only recently turned positive for the first time since fall 2008—it did help Guess? Avoid steep merchandise markdowns to pull shoppers into its stores.

This tough stand on pricing has bolstered revenues now that mall traffic is on the rise and Americans are once again opening their wallets.

Guess? also benefits from a more diversified business model than many of its peers. Retail operations are its bread and butter and account for almost half of its revenues. Wholesale operations generate 14 percent of revenues, while 5 percent comes from licensing the use of its name for a variety of fashion accessories.

A decade ago almost 90 percent of the company’s business was in North America. Since then, the retailer has made significant inroads into both European and Asian markets, which now account for 37 percent and 7 percent of revenues, respectively.

And there’s plenty of room for growth. Management plans to grow its North American store count by 12 percent in 2010, and its plans for growing Asian markets are even more ambitious. This year management expects to open 136 new stores in Asia.

What’s more, Guess? has implemented extremely effective cost control measures over the past two years, slashing selling, general and administrative expenses—the biggest drag on improving margins—and bumping its operating margin to 11.7 percent.

The company also has stepped back the amount of inventory it keeps on hand, reducing the need for discounts to move older merchandise, another boon to margins.

Finally, the company has benefited from management’s close attention to improving its balance sheet and reducing debt.

Guess? currently has a cash balance of $500 million, leaving it well positioned to internally finance its expansion efforts.

And with almost $5-per share of cash on hand, the company is prepared to weather any storm in style.

Why to Buy, GUESS? (NYSE: GES, $41.62)

• Tight Cost controls are generating impressive margins
• Strong growth prospects in Asia and Europe
• Almost totally self-financing