Thanks to increased security, unavoidable delays and transit time on two-leg trips, travellers can often feel they spend as many hours in airport lounges as they do flying.
So it's no surprise that most airlines consider their lounges a vital part of the travel equation, especially when it comes to wooing frequent flyers.
When it comes to a lounge on home turf, every airline puts its best foot forward.
Just as seats and inflight dining at the pointy end of the plane continually advance as airlines fight for business class bums and their corporate budget, there's no resting on your lounge laurels.
Qantas is now half-way through a major overhaul of its international lounge network with the opening of an all-new haven for the well-heeled at Singapore's Changi Airport.
Built to replace the well-worn business class and first class lounges which previously ran under the now-abandoned joint venture with British Airways, the Qantas Singapore Lounge is a fresh concept for the Red Roo.
Along with borrowing design elements from its Sydney and Melbourne siblings, food and wine at the Singapore lounge comes under the stewardship of Neil Perry and his Rockpool team.
But there's a decidedly Singaporean touch, from the Asian influences of Perry's Spice Temple restaurants to hawker-style cooking hotplates and communal dining tables.
When you add the cocktail bar and a valet service to press your shirt and shine your shoes, the new Qantas Singapore Lounge could very well be the world's best business lounge.
Next up for Qantas will be a makeover for its Hong Kong lounge, along with a new business lounge at Los Angeles in late 2013 and a new LAX first class lounge in 2014.
The airline's intent is to see each new lounge raise the bar for its competitors – and Qantas has plenty of competition.
On the home front, Singapore Airlines will begin a worldwide refresh of its SilverKris lounges, starting with the Sydney lounge in May. Virgin Australia and Etihad have pencilled in a years' end launch for their new shared lounge at Sydney International Airport.
Here's a run-through of five very different types of airport lounges, including a few you may not have heard of.
The flagship lounge
When it comes to home turf, every airline puts its best foot forward.
Take the Qantas First Lounge at Sydney, with its "mini Rockpool" restaurant and Payot day spa offering free facials, massages and manicures.
The swish Virgin Atlantic Clubhouse at London's Heathrow Airport combines its day spa with a Bumble & Bumble hair salon and tanning booths.
Also at Heathrow, the British Airways' Concorde Room boasts a champagne bar and hotel-like private rooms with a day bed, ensuite bathroom and room service to order your meals and give your shirt, pants or skirt a quick press.
Thai Airways' Royal Orchid Lounge at Bangkok lays on the full Thai spa treatment with elegantly appointed treatment suites and a choice of oils for your full-body massage.
Lufthansa goes one better with an entire terminal dedicated to passengers flying in first class from their home base in Frankfurt.
It's less like a lounge than a private luxury hotel, with a bar stocking over 80 different kinds of whiskey, a cigar lounge and soaking baths. A chauffeur-driven Mercedes or Porsche takes you from the terminal to the tarmac, right up to the plane's first-class stairway.
The VIP lounge
As lush as those lounges sound, there's one more rung on the status ladder. Welcome to the world of invitation-only lounges, where no amount of frequent flyer points will open the door.
These exclusive lounges exist to stroke elite egos: politicians, celebrities and the upper ranks of Australia's largest companies.
Qantas set the trend with its Chairman's Lounge, which its CEO Alan Joyce once described as "probably the most exclusive club in the country".
Virgin Australia is busy rolling out its own version of the Chairman's Lounge, known simple as The Club.
However, airlines are loathe to discuss these lounges beyond acknowledging their existence and it's rare to even see photos of what lies beyond those frosted glass doors.
The arrivals lounge
While relatively few in number, arrivals lounges are a Godsend to the long-distance traveller – especially when your flight lands in the wee hours of the morning.
They provide a place where you can freshen up with a shower, grab some breakfast, catch up on emails and generally take a breather before heading to the city.
Cathay Pacific has a compact arrivals lounge at Hong Kong airport that's perfect for a recharge when you step off the red-eye from Sydney.
Aside from a buffet breakfast, British Airways' sprawling arrivals lounge at Heathrow T5 has almost 100 individual shower suites, plus a valet service to press your clothes so you'll look as sharp as when you set off on your journey.
The express lounge
It's the lounge you have when you don't have a lounge.
Air New Zealand, so often an innovator in this staid industry, chose Christchurch to open its first Koru Express lounge.
This compact space sits at the departures gate and is part of the adjacent airport cafe, which supplies the staff, food and drink.
It's more like a brunch bar than a proper lounge, and is intended for fairly short stays and time-pressed business travellers.
It's an idea that more airlines should embrace, especially in smaller airports that can't justify the cost of a larger and more conventional lounge.
The kid-free lounge
Do you belong to the "they shouldn't let kids into business lounges" brigade?
Then Virgin America's The Loft lounge at Los Angeles Airport may be the start of a trend you'll champion.
In a brave move, considering the US obsession with individual rights and lawsuits, Virgin America has banned children under 12 from The Loft.
Oddly enough, Virgin Australia passengers are the exception to this rule. Under an old legacy access policy between the Aussie and American Virgins, children flying on Virgin Australia can use the lounge as long as they're escorted by an adult over 21.
What are your favourite airport lounges?
David Flynn is a business travel expert and editor of Australian Business Traveller.