Topshop finally hopped across the pond to New York City in April 2009. Anthropologie, headquartered in Philadelphia, Penn., signed a lease on London's Regent Street to open its first store in Europe by the end of this year. And Thailand's firstGap is set to opens its doors next spring.

Regardless of how badly retailers' sales have suffered through the recession--in June 2009, U.S. retail sales saw a year-over-year decrease of 9%, to $342.1 billion, according to the Commerce Department, and Saks' ( SKS - news - people ),Gap's ( GPS - news - people ) and H&M's year-over-year global sales for stores open at least one year were down 4%, 10% and 5% in June, respectively--there's no denying that many have used this as an entrée into markets beyond their country's borders. That's because expanding abroad is one of the most efficient ways for a brand that has saturated its own country's retail landscape to gain global market share and increase sales. The result? More choice for the consumer, from Hong Kong to Hamburg. And (hopefully) a bigger bottom line for retailers.

In Pictures: World's Shopping Capitals

Consider London. In the U.K., the High Street--or the main road in a neighborhood--is shopping mecca. In London, there are more High Streets than one can count, so it's no surprise it hosts more than half of the world's top retailers--chosen for their market share both in their home country and abroad--including the young and trendy Topshop as well as high-end department stores like Liberty of London and Harvey Nichols.

What's more, London's leasing regulations for real estate occupied by a foreign-operated business are a lot less strict as they are in, say, Mumbai--where foreign retailers are forbidden to directly open single brand stores--according to Peter Gold, head of Europe, Middle East and Africa cross-border retail research at Los Angeles-headquartered CB Richard Ellis Group ( CBG - news - people ), a multinational real estate corporation. That means retailers like the Gap, Abercrombie & Fitch ( ANF - news - people ), Uniqlo and Urban Outfitters( URBN - news - people ) have often used London as a launch pad for foreign expansion.

It also means that shoppers in London have the most options when it comes to browsing the world's top retailers. Indeed, 59.26%of the world's biggest and best stores are open for business in the city.

Behind the Numbers 
To find the world's best cities for shopping, we turned to Gold, who co-authored CBRE's spring 2009 study "How Global Is the Business of Retail?" Gold and his colleagues mapped the global footprint of 280 of the world's top retailers across 67 countries, analyzing retail globalization at a city level. Cities that possessed the highest percentage of these top retailers--chosen for their market share both in their home country and abroad--capped off the list. Retailers studied included restaurants, luxury goods purveyors and mass-market discounters. (The only retailers not considered were automobile dealerships and manufacturers.)

The more options a shopper has, the more discerning he seems to be.

"London shoppers are most adventurous, full stop" says Jason Campbell, a personal stylist and founder of online fashion publicationJC Report. Londoners' style is all over the map, and that's reflected in what the stores carry for the runway collections."

While London has its fare share of mass retailers, niche boutiques are peppered across the city, from Westbourne Grove to Shoreditch. For instance, Comme des Garçons designer Rei Kawakubo's Dover Street Market in Mayfair features hard-to-find designers like Anne Valerie Hash; Labour of Love in Islington stocks little-known labels such as Louis Amstrup.

Paris' shoppers--with 49.79% of the world's top shops at their disposal--are similarly selective, although favorite boutiques tend to showcase French designers or those who show their collections during the city's Fashion Week, says Campbell. The latest shopping hot spot? Palais Royal in the first arrondissement, which hosts boutiques such as Stella McCartney, Rick Owens and Corto Moteldo. Diane Pernet, a fashion journalist and author of the Where to Wear, Paristravel guide, suggests new vintage shop Bastien de Almeida as well as Maria Luisa, Colette and L'Eclaireur for those who love multi-brand boutiques. Designer Isabel Marant's boutique in the Marais is also a must-visit for fashionistas looking to add some Parisian ease to their wardrobe.

Other popular shopping destinations include New York, Tokyo and Dubai. While New York (hosting 46.91% of the world's top retailers) and Tokyo (38.68%) both offer tourists a bigger selection of stores than any other city in their respective countries, Dubai's No. 4 ranking on the list--boasting 45.68% of top retailers--is an indication that demand in the Middle East just keeps growing. For example, by 2010, American department store Bloomingdales, part of Macy's ( M- news - people ), will have opened up shop in the city. Along with a consumer demand for more brand names, the numerous malls and shopping centers being built within Dubai make it easier for retailers--or their franchise partners--to acquire prime real estate at a reasonable price. "Access to real estate is key," says Gold.

Other emerging markets are also going strong, including Russia's Moscow--where, Campbell says, conspicuous consumption is still socially acceptable if you do indeed have the money to spend--and Beijing and Hong Kong in China--where 50 new millionaires emerge every day, according to Dan Sontag, president of the global wealth management group at Merrill Lynch. However, brand names still lack a real presence in cosmopolitans within India and Brazil. That's because these countries have stricter rules when it comes to foreign retailers operating businesses within their cities, regardless of whether or not it's through a franchise agreement. Both India and Brazil have strong domestic retail and luxury industries and don't want to cannibalize those sales, says Gold.

But not to worry, power shoppers. Gold also says that as the demand for global brands increases in these countries, so will their brick-and-mortar presence: "I think that it will change," he says. "There is too much [financial] opportunity."