(CNN) -- There are airport lounges and then there are lounges that make you forget you're at the airport.
Posh surroundings, gourmet food, spa treatments and impeccable service can transform waiting for a plane into a luxurious treat or a productive time away from the office.
So it's wise for airlines courting the first- and business-class crowd to not just focus on the in-flight experience, but also consider how to improve the many hours on either end of the journey, said Gary Leff, a frequent flier who writes the blog, View from the Wing.
That's especially true these days with the unpredictable nature of security forcing fliers to arrive ever earlier at the airport.
"You wind up with a lot of downtime because it's never really certain how long these things are going to take, so there's a lot of potentially lost time and it's also the last opportunity to be productive often times before a long flight," said Leff, who flies about 100,000 miles a year.
"So for a business traveler having that comfortable, quiet, productive space is really quite important."
Leff looks for a relaxed setting with good Internet access, tasty food and impeccable service. He enjoys the perks so much that he chooses to redeem his frequent flier miles for first rather than business class in order to enjoy some of the really special airport lounge amenities.
"The best, best, best experience is one where it's really a carefree experience; where effectively it's not your job to pay attention to when it's time go to," Leff said. "
"Someone will keep you updated if your flight's delayed, but their job is to come get you and bring you to the plane when it's time."
Leff is also a fan of arrivals lounges, which allow fliers to relax, eat and take a shower after a long flight. They're especially useful for travelers who have to head to a meeting soon after their journey and want to refresh, or aren't able to check into a hotel if they've arrived at their destination in the morning, he said.
We asked Leff to name some of his favorite airport lounges around the world. Here are his top five choices:
Thai Airways First Class Lounge, Bangkok
Passengers begin their journey at an exclusive check-in area, so there is virtually no waiting for security and passport control.
Once all formalities are complete, golf carts whisk them inside the lounge, where they can relax in semi-private rooms -- facilities that Leff described as living rooms with couches and chairs. There's also "a room of food" to enjoy, he said.
Travelers can book a spa treatment -- including a 30-minute neck and shoulder or foot massage, or an hourlong full body massage -- in their own private spa bungalow.
"There's a tremendous number of staff to serve whatever you need and the spa experience is outstanding," Leff said. "Then you get on a long-haul flight, boy, you're relaxed."
Lufthansa First Class Terminal, Frankfurt
This separate terminal, which the airline likens to a small luxury hotel, also has its own exclusive check-in and security checkpoints. (Leff called it the most polite security he's ever experienced.)
Passengers can while away the time before their flight in leather armchairs and sofas or nap in comfy daybeds. Those who wish to relax with a spirit have plenty to choose from, including 80 different brands of whiskey.
There is a top-quality restaurant, a cigar lounge, and wonderful shower and bath facilities, Leff said.
Every passenger also gets his or her own personal assistant
But Leff's favorite part comes right before the flight: Guests are chauffeured to their plane in a Porsche or a Mercedes-Benz.
"There is something cool about being driven across the tarmac, maybe driving behind a 747, to get to my plane," Leff said.
Virgin Atlantic Clubhouse, London
The airline calls relaxing in this stylish business class lounge the ultimate pre-flight experience.
"It's just an architectural marvel," Leff said. "The service is good, the food is good, the facilities are good and it's interesting and impressive."
Order a colorful cocktail from the 14-meter (45-foot) bar or indulge in menu selections such as potato and watercress soup, smoked salmon and scrambled eggs, or duck à l'orange.
The cool decor includes a ceiling to floor Japanese water wall and a den with a pool table and video game consoles.
JetQuay Terminal, Singapore
This lounge at Singapore's Changi Airport is not airline-affiliated, so access to it isn't included in the price of your ticket. Rather, it is available to passengers traveling in any class for an extra fee.
"It's the standalone terminal with the escort to and from the plane and the private immigration -- that's something that doesn't exist in a lot of places," Leff said.
If you're departing from Singapore, staffers will take care of your baggage, help you with travel formalities, and when it's time for you to depart, drive you to your gate in a buggy.
If you're flying into Changi Airport, they will meet you on arrival and help with immigration clearance and luggage.
The lounge's amenities include a business center, private meeting rooms, board room, massage chairs, showers, nap rooms and free Internet access.
The Wing, Cathay Pacific First Class Lounge, Hong Kong
Dubbed by the airline as "the world's most exclusive balcony," this spacious lounge overlooking the terminal and the runway includes The Library, for quiet reading, and The Haven, for dining.
Leff particularly likes The Cabanas -- private bath and shower suites complete with lounge chairs.
"They're shower rooms but they're large, that have not just showers but sort of a little deck in back that looks out on a creek inside the lounge," Leff said.
"It's just a very relaxing arrival experience if you're connecting to another flight."