Modern-day airports mix transportation nodes with hospitality centers, focus on customer experience and offer fine dining outlets, luxury shopping outlets and full-service spas.
That said, which airports do it best? Each year, Airports Council International — the trade association of the world's airports — conducts extensive passenger surveys to find out.
For its 2015 Airport Service Quality Award rankings, ACI surveyed more than 550,000 travelers worldwide about their traveling experiences. They ranked airports on everything from check-in and security to on-site amenities and food, beverage and retail options.
"Airports have evolved into complex, customer-focused businesses in their own right that in many cases are in competition with each other for passenger traffic," said Angela Gittens, director general at ACI World.
"From duty-free and restaurants to ambiance, cleanliness, courtesy of staff, amenities, efficiency and more, air travelers are expecting big things from the airports through which they travel," she added.
For the fourth year in a row, Indianapolis International landed in the first-place slot for airports in North America. The hub, which serves more than 7 million passengers a year, rolls out the red carpet for fliers who enter its gates. It has an extensive art program, many branches of local eateries, an apiary, a giant solar farm and a roaming robot that answers customer questions in real time.
"When you combine a beautiful facility with a generous dose of Hoosier hospitality, great things happen," said Angela Cain, director of public affairs at Indianapolis' Airport Authority.
"We are grateful to the hard-working Indianapolis Airport Authority staff, as well as our many business partners, for the customer service excellence they provide every day to our travelers," she added. "We wouldn't win this award, for the fifth time in six years, without them."
Tied for second place among North American airports for 2015 were Grand Rapids' Gerald R. Ford International Airport, Tampa, Dallas Love Field, Jacksonville and Ottawa.
Third-place for North American airports also resulted in a tie, for Austin, Detroit, Sacramento, San Antonio, and Toronto's Billy Bishop Airports.
"These awards are particularly meaningful, because they are based on real-time feedback from our customers, while they are traveling," said Thomas Naughton, CEO of Wayne County Airport Authority, which operates the Detroit Metropolitan Airport.
For Best Airport in North America serving under 2 million passengers, Maine's Portland International Jetport took top honors.
No North American airport "placed" when survey results were ranked by airport size. However, among the largest airports (those serving more than 40 million passengers a year) there was a two-way tie for top honors. Seoul's Incheon Airport — which boasts a skating rink and a golf range — and Singapore's Changi Airport, which has a rooftop pool, a four-story slide and a butterfly garden, were the winners in that area.
In a new category of best airport by size and region, Grand Rapids' GRR was the North American region winner for airports serving two million to five million passengers. Separately, Indianapolis International Airport won in the same category for airports serving five million to 15 million passengers.
Among airports serving over 40 million passengers a year in this same category, Seoul Incheon Airport took first place in the Asia-Pacific and London's Heathrow Airport topped the list in Europe.
You can see the full list of the ACI 2015 Airport Service Quality Award winners on its website.
—Harriet Baskas is the author of seven books, including "Hidden Treasures: What Museums Can't or Won't Show You," and the Stuck at the Airport blog. Follow her on Twitter at @hbaskas. Follow Road Warrior at @CNBCtravel.