With a few exceptions, the airports of yesteryear were grim assemblages of hangars, tunnels and waiting pens more suited to cattle than humans. Lines snaked into eternity, edible food was scarce, and traversing between gates required more than a little resilience.

How times have changed. Today's best airports are closer to upscale malls, offering services and distractions like swimming pools and fitness clubs, expansive shopping facilities, play areas for children, first-rate hotels for overnights and in some cases, even fine art. Some of these places are starting to attract people who don't have a plane to catch.

"It's becoming increasingly clear that an airport which aspires to improve the level of comfort and convenience for the passengers who travel through it will have an advantage over those that don't," said Adrian Bridge, Commissioning Editor at the travel section of Britain's Daily Telegraph.

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In fact, many clued-in travelers are now choosing carriers because of what that airlines' hub - whether that happens to be Lufthansa's second offering in Munich, or Swiss International Airlines' primary one in Zurich - is offering: in these cases, sparklingly beautiful exercises in design and efficiency.

For many years, the airport to beat has been Singapore's Changi, which as a regional hub has outshined many of its fresh-faced competitors in Asia and become a favorite for the traveling cognoscenti.

"For me, the most important thing is a short turn-around time," said Leisa Kenny, the Director of Sales and Marketing for Karma Resorts, "and no airport does that job better than Changi. Plus, there are top-notch shopping, fitness and shower facilities available to anyone. Best of all, there are complimentary Internet and charging facilities."

Kenny, who is based in Bali and travels around Asia via Changi, says the airport's benefits are apparent: "For those of us who have to do the nightmarish overnight stay, you can choose the airport's Transit Hotel to bed down for the night without even having to clear immigration, saving time the next day," she said. "That, to me, is priceless."

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 And things are looking up here in the States, where for decades passengers have been relegated to dank, pre-fabricated terminals that date back to the dawn of the jet age. Now passengers are enjoying the fruits of a late 1990's terminal building boom; at least 10 cities around the country have new facilities - including Seattle, Miami, Detroit, New York's John F. Kennedy and Los Angeles.

The most promising is Dallas-Fort Worth International Airport's $1.4-billion Terminal D. Serving an estimated 5.6 million international passengers, the state-of-the-art 28-gate terminal offers the requisite smattering of shops and a posh 298-room Grand Hyatt Hotel, Wi-Fi access and a security screening center with three walk-through explosives-detection machines capable of processing 2,800 passengers per hour.

Back in Asia, meanwhile, new airports like Nagoya in Japan (with its unparalleled food court and popular viewing terrace) and South Korea's Incheon are sidling up to stalwarts like Hong Kong, whose Regal Airport Hotel feels like a resort.

The airport hotel is naturally a big priority. According to Nigel Page, Senior Vice President of Commercial Operations at the Dubai-based airline Emirates, "hotels are a boon when you're really tired." And the airline's Dubai hub, which is already lauded as one of the world's best in terms of shopping, features a 100-room hotel with a gym and health spa.

And as upgraded amenities increasingly become standard fare, some airlines have decided to create entire terminals dedicated to their premium passengers.

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Witness Lufthansa's euro30 million First Class Terminal, reserved exclusively for the airline's first class passengers or elite frequent fliers. Passengers relax in a sleek space awash in creamy leather furnishings, dine on a Do & Co a la carte menu and refresh themselves with monsoon showers and marble baths.

In the Premium Terminal at Qatar's Doha International Airport, meanwhile, passengers get the same sort of treatment but can also have a run at a state-of-the-art game room with PlayStations and other amusements.

"Transiting through an airport with state-of-the-art five-star facilities makes a world of difference on a long business trip," said Anna Nash, Public Relations Executive for Orient-Express Trains & Cruises, who recently flew through Doha. "The exclusive, almost hotel-like feel of such facilities makes the layover more pleasurable, offering the choice of relaxation or time to catch up on business matters."

In Singapore, meanwhile, the country's lauded flag carrier says that one of the main reasons for their unrivaled success is their base of operations at Changi, whose hushed environs, lily ponds and palm courts are welcome tonic for the millions of tired long-haul transcontinental passengers who travel through it each year.

"It's clear that the benefits of the airport including the rooftop pool, the hotel and other amenities make this a preferred and repeated choice for our valued customers," said John Cotton, a spokesman for Singapore Airlines.

The airport is connected to the city center by Mass Rapid Transit but with cabs so cheap, most travellers just hop one. Of course that's not true everywhere, which is why Hong Kong's Chek Lap Kok, Zurich Airport at Kloten and Munich Airport International---all with streamlined rail links---figure highly on our list. Munich is located 45 minutes outside of the city center by S-Bahn or overland train, but there are plans for a high-speed magnetic levitation train that will make the 37 kilometer journey in just 10 minutes at speeds of up to 310 m.p.h.

It's obvious that the world's leading airports are out to create new standards of comfort and convenience and not merely content to sit idly by, said Bridge, the Daily Telegraph editor. "In that sense, more and more passengers will wherever possible seek to avoid airports where services are limited, outdated or below par."

In addition to the contributors quoted above, we consulted a number of frequent business travelers and industry experts to generate a list of the best airports in which to spend a long layover. These airports are far more than just way stations"they're destinations in their own right. And many of them feature surprises.