At the Alvear Palace—widely considered the top hotel in South America—it's still possible to feel as rich, as they used to say, as an Argentine. The colossal neoclassical chateau, which dominates a gilded swath of Recoleta studded with Cartier, Polo, and Zegna outposts, has been the focus of Buenos Aires high society ever since its polished brass doors opened in 1932. These days, the grande dame remains in exceptional form, from the attentive bilingual butlers to the opulent suites full of Louis XV-style furniture. Guests should be sure to have a tipple in the magnificent Lobby Bar, where the local upper crust and visiting sultans gather for cocktails, gossip, and political intrigue. The Alvear's top-notch French restaurant, La Bourgogne, is the country's only Relais Gourmands establishment.

When you step into the Art Hotel—located where the tony barrios of Recoleta and Barrio Norte intersect—you might feel as if you've wandered into an art gallery. As it turns out, you have: The ground-floor lobby of this smart, Euro-style "hotel de chârme" doubles as a gallery space devoted to contemporary painting, and the entire space—a radiantly revamped 85-year-old townhouse with 35 well-appointed rooms—suggests that great care has been taken with every aesthetic decision. Highlights include the elegant, twisting marble staircase; the assorted curlicued ironwork; and the rooms themselves, some of which have canopy beds, and all of which have refined, minimalist furnishings.

Bourgeois and bohemian, rebel and conservative.…The various slogans of this chic little oasis are improbably taken from a book by the American political pundit David Brooks (Bobos in Paradise, about the emerging class of "bourgeois bohemians"). Even more improbably, the slogans almost make sense in context. Situated on a dappled tree-lined block in Palermo Viejo, the Bo Bo is both a hipster hangout and an urbane boutique hotel, as evidenced by the inviting lobby café restaurant (featuring an inspired Argentine-Mediterranean-Asian menu), with its sleek furnishings, grenadine-hued velvet curtains, pulsing electronica soundtrack, and black-uniformed staff. Housed in a 1920s mansion, the hotel's seven airy rooms range in style from minimalist to Art Deco to "Argentinean" (a top-floor suite with a skylighted Jacuzzi), and many come equipped with their own private balconies.

This self-described "pop hotel" may have been named after a novel by Manuel Puig, but the overall vibe is more cinematic than bookish. It's as if David Lynch and Mickey Rourke had teamed up to create an inspired stage set devoted to the twin joys of surrealism and seediness. Presiding over a distressed corner in Constitución (on the outskirts of San Telmo), Boquitas Pintadas—which opened in 2000—offers six rooms with evocative names like Gilda and Santeria, each of which is a private reliquary of thrift-shop furniture and oddball objets. Frequent redesigns offer ideal excuses for blowout reopening parties in the popular street-level cocktail bar, which plays host to a nightly cast of DJs and arty slummers from around the globe.

Amid prestigious apartment buildings and museums and art galleries, CasaSur is aimed at those seeking the cachet and convenience of a Recoleta address at an affordable price. The corner of Callao and Quintana ranks among the costliest real estate in the country, and this 36-room hotel projects itself commensurately, with a lobby of lacquered rosewood filled with scented candles and fresh lilies, a fastidiously finished interior with acoustic-layered wall fabrics that dampen ambient sound, and staff who exude formality and discretion. Room decor favors traditional elegance over experiment, with gold silk and black velvet softening robust furniture and lapacho-wood flooring. Yet the building itself is almost anorexic in its proportions, with 13 floors soaring over a lot barely 30 feet wide. As a result, the standard rooms feel somewhat cramped, and steam from the spa's super-heated plunge pool billows directly into the massage parlor. Nevertheless, catering company Croque Madame, which operates a string of cafés in patrician locations, serves well-presented tapas in the wine bar and delivers it—and fruit-laden breakfasts on silver platters—to guests' rooms.

This impossibly cute little red "guest house" on a colorful and quiet side street in Palermo Soho is a great (and inexpensive) find. The minimalist decor matches the minimal tariffs, making the traditional Palermo home with its small courtyard a favorite of both the bohemian and backpacking crowds. Some rooms have their own bathrooms, and some don't, but all are functional and spotless, including the Romper Room-like attic accommodation (the keepers of Che Lulu like to call it a "pop Eastern space") known as Tres Geishas. The young staff is friendly and informed, and the breakfast—coffee, medialunas (croissants), and dulce de leche—is excellent.

San Telmo was once the city's wealthiest district, with row after row of neocolonial townhouses and mansions. An 1871 yellow-fever epidemic sent the barrio into long decline, but a gritty, streetwise crowd is starting to return, drawn by antiques markets, no-frills parrilla steakhouses, and swinging late-night bars. Aptly, the Cocker, a five-room design guesthouse, is a case study in urban rescue. Britons Ian Spink and Aidan Pass snapped up a rundown but grandiose mansion, restoring its pinotea floors, handmade wrought-iron window frames, and soaring ceilings with fastidious attention. Renovated antique chairs, sofas, and beds (and even a Chappell grand piano) are displayed with theatrical flair in the five idiosyncratic rooms: Old balustrades now frame a monster bed in one, and a four-poster supports a "floating" bathroom in another, while cushions, drapes, and yards of muslin transform ordinary nooks into intimate dens. The twisting corridors and spiral staircases invite exploration, eventually opening onto a terrace garden planted with honeysuckle and a commanding rooftop pergola.

Aimed at low-profile travelers with impeccable taste, Costa Petit is a design-minded boutique hotel in Buenos Aires' Palermo Soho district. The two rooms and two suites are decorated with velvet, restored wood furniture, and rustic wall paneling. The owners, cabinetmaker Diego Padilla and interior decorator Eugenia Chorén, salvaged 19th-century lamps, wicker sofas, club chairs, and aged pinotea ceilings from architectural demolition sales.They also found new uses for old curios: a wrought-iron baby crib functions as a towel stand, and planks of caldén hardwood, cut cross-grain like butcher's block, now serve as robust flooring. The property was once a mechanic's workshop: A vehicle inspection bay has been transformed into a turquoise-tiled pool, surrounded by a brace of Italian cypresses and a lone olive in the jasmine-draped garden. Space is too cramped for a restaurant, but the staff serves a sumptuous in-room breakfast and can arrange anything from yoga sessions or polo practice to a day's yachting on the Río de la Plata.

"It's not just a hotel," the people who run this monstrous property in chic Puerto Madero Este (a.k.a. the Tribeca of B.A.) will tell you, "it's a universe." They may have a point. The buzz has died down a bit since it opened in 2004, but the Faena Hotel + Universe—the brainchild of Argentinean fashion guru Alan Faena and design superstar Philippe Starck—intends to be an all-purpose 21st-century Baroque fun house. The former granary, a hulking brick structure from 1902, contains two formal restaurants, including the Alice in Wonderland–inspired El Bistro; a produce market; hopping nightclub; luxe spa with hammam; wine cellar for tasting parties; and jasmine-hedged outdoor pool. Usefully, the hotel assigns you an "experience manager" who can hook you up with tango lessons, polo matches, or just a compass to help you get around.

A favorite choice of such diverse guests as Robbie Williams and Fidel Castro (can't you just imagine them partying together?), the lordly Four Seasons Buenos Aires is, in fact, two hotels in one. There's the 13-story tower built in 1992 (formerly the Park Hyatt), with its flower-filled lobby and elegantly mod, amenity-rich guest rooms (the decor incorporates lots of dark wood and luxurious but calm-colored fabrics). But the real jewel is out back, next to the pool: La Mansión, a fanciful Belle Époque manor, complete with Louis XIII-style lobbies, banquet rooms, and 2,000-square-foot suites done up in Carrara marble and Slovenian oak. And if that still seems like a tight squeeze, you can always rent the whole mansion.

The gleaming, futuristic Hilton Buenos Aires, designed by the esteemed Argentinean modernist Mario Roberto Alvarez, opened in 2000 in ultra-chic (and rapidly developing) Puerto Madero Este, formerly a landscape of 19th-century docks and warehouses. The Hilton played a starring role in the 2000 Argentine film Nueve Reinas (Nine Queens), and it retains a certain kind of glass-and-chrome glamour, particularly in the breathtaking seven-floor atrium lobby. Many of the 418 amenity-stuffed rooms—and the stunning rooftop pool—have sweeping views of the old docklands and the wilds of the Costanera Sur ecological reserve.

Aimed at the hip, partying crowd increasingly drawn to Buenos Aires' late-night pleasures, Home was the first hotel to open in fashionable Palermo Hollywood. Brainchild of British music producer Tom Rixton and his Argentinean wife, Patricia O'Shea, the 19-bed property is within stumbling distance of fashion stores, film studios, and a bunch of modish bars and restaurants that never seem to close. Guests can fire up the fiesta at Home's bar, where maestro barmen mix signature cocktails like the rosemary and sorrel vodka martini. The rooms, enlivened with strips of vintage French wallpaper, have Eliel Saarinen-designed queen beds, while suites have king beds, sofas, hot tubs, and balconies. Two aptly named palo borracho ("drunk trunk") trees stand guard over a jasmine-draped deck, a parrilla (grill), and lush gardens. A basement spa offers Ayurvedic, Shiatsu, and Esalen treatments.

This stylish town house in the Palermo Soho is owned by Francis Ford Coppola, who spent two years in the terra-cotta-painted house before opening it as a tastefully rustic and homey property, with patinaed brick floors, indigenous Peruvian tapestries, and floor lamps fashioned from willow. Guests can splurge on the whole house or choose either the two-bedroom wing with a pergola and a scent-laden herb garden or the main building's 1,400-square-foot four-bedroom upper floor. Both sections overlook the courtyard garden, where the silence is broken only by the song of mockingbirds. The service is ultra-discreet: A manager, concierge, and sommelier are on hand, but they're usually out of sight (cell phone at the ready) unless required. Breakfast, prepared by a local pâtissier, is delivered daily, and for dinner, guests can dine locally or do as Coppola did—feast on an Argentine-style barbecue.

The spirit of Argentine dance legend Carlos Gardel presides over this "Residential Tango Academy," lovingly crafted by artist Héctor Villalba from a 1903 Italianate mansion in San Telmo. This is tango—combined with five-star service—to the max: Multiday packages feature hands-on tutelage from visiting maestros, and the Wednesday-night milonga (tango party) has become a choice destination for aficionados from around the city and the globe. But the Dandi is also ideal for just putting your feet up: The various lobbies and rooms—including the stand-out Astor Piazzolla suite—are outfitted with overstuffed chesterfields and finished off with murals depicting scenes from the handlebar-mustache era. For budding tangueros looking to replenish after a day of windmilling around one of Dandi's deluxe ballrooms, there's a roof-deck pool and the inviting Patio Andaluz, an enclosed courtyard that's perfect for late-night cocktails or a boisterous asado (barbecue).

The stately Plaza Hotel—with its elegant French facade overlooking the leafy oasis of Plaza San Martín—has been a Buenos Aires landmark ever since opening its doors in 1909. Designed by Alfred Zucker (whose best-known work is St. Patrick's Cathedral in New York), the nine-story Plaza—once upon a time the Buenos Aires Ritz—has a rich history of attracting royalty, cattle barons, and the globe-trotting polo crowd. Marriott snapped up the legendary luxury establishment in 1994 and has astutely combined modern amenities (the hotel was further renovated in 2003) with classic, white-glove sophistication, all at very reasonable prices. Be sure to log some time at the handsome Plaza Bar, a favorite Art-Deco haunt of B.A.'s movers and shakers.

In 1929, modernist architect Johannes Kronfuss designed a dramatic Art Deco edifice two blocks from the Casa Rosada, Argentina's presidential palace. Despite being declared a heritage building, Kronfuss's creation fell into ruin in the 1990s, along with much of the Montserrat district. Recently renovated as a 39-room hotel, the seven-story building has a graceful fluted stone exterior, while an accordion-gated elevator still clunks past landings lit by stained glass windows. Rooms range in size from the generous to the enormous; all have 13-foot ceilings, expansive iron-framed windows, and Art Deco-style furniture upholstered in iridescent sea green. Don't be afraid to ask for extras like babysitters, personal trainers, or masseurs—inexplicably, the youthful staff may forget to detail what's on offer. Guests may also customize the contents of their minibar or borrow a laptop.

The stylish Jousten hotel, built in 1928, was long a favorite hangout of the Buenos Aires upper crust, hosting the likes of Juan and Evita Perón. After a long decline, the storied property was bought by the Spanish NH chain and returned to its original charm: The Jousten's ornate white facade is a beauty, a kind of Art Deco–era Venetian palazzo, and the interiors—with painted Spanish tiles, generous wood moldings, and ornate columns—suggest a felicitous marriage of modern boutique-hotel design and Old World European-style luxury. The central location—near the Plaza de Mayo and looking out over Puerto Madero—makes it one of the top business and tourist hotels in town.

Shaded by centennial gomero and tipu trees, and well situated between the Vatican's palatial embassy and the Addams Family–style Residencia Maguire, Park Hyatt's Palacio Duhau has made a splash since opening in June 2006. Divided between a restored Belle Époque mansion and a contemporary addition (museum-quality art, renewed every 45 days, is displayed in an underground walkway connecting the two buildings), the hotel's paneled corridors and light-filled lounges ooze discreet wealth. There's marble aplenty if you look for it, but the emphasis is on classic materials and clean lines, with low-slung leather furniture, frosted-glass lamps, and pale wood tempering the mansion's ornate original plasterwork. It's difficult to fault the 500-label wine library, the on-site cheese store, and a bar with 17th-century oak (the Duhau family's former safe now houses the bar's collection of cognac and cigars), nor the soothing air of the gym and spa, with a phalanx of attendants, myriad treatment suites, and an Olympic-size swimming pool.

They say you can see all the way to Uruguay from the upper reaches of this 23-floor luxury high-rise, a strikingly mod edifice—and handy orientation landmark—overlooking Plaza San Martín. The views inside the hotel are pretty impressive, too: There are the 181 Biedermeier- and antique-filled rooms (including the outsize Presidential Suite); the elegant Lobby Lounge; the welcoming Crystal Garden restaurant; and the soothing outdoor pool (open seasonally), watched over by the Torre de los Ingleses, B.A.'s version of Big Ben. Appealing to corporate-carders and pop stars alike, it's no that wonder the Park Tower—which is conjoined with the neighboring Sheraton—ends up on so many "best of" lists.

Stellar service is the draw at the 144-room Sofitel Buenos Aires—for instance, the concierge once sourced a pedigreed dog at short notice for one demanding guest—but comfort comes in a close second. A 1928 Art Deco tower, flanked by two neoclassical wings, houses 144 cleanly styled rooms decorated with pastel tones, leather furniture, and black-and-white photographs of Paris. Fresh flowers in each bathroom complement the subtle use of aromatherapy scents. The standard suites are spacious enough, but the presidential suite encompasses the entire 17th floor, complete with Indochinese decor and a view stretching across the Río de la Plata to Uruguay. Sip on a well-mixed martini in Café Arroyo, sample French gastronomy in the Le Sud restaurant, or simply curl up with a book in the Bibliotèque, a cozy nook draped with velvet.