Much like the houses in Harry Potter, one of the core questions every fan asks themselves of Avatar: The Last Airbender is which bending style they would want to have. Usually, the choice comes down to water, fire or earth. But it shouldn't be. Air is the element that would be the most useful, and the series itself proves that. It may be the most overlooked bending art, but there's just no doubt that airbending would be the best of the four you could choose for yourself.
It's easy to see what's so appealing about the other three elements. First and foremost come the subskills, with every other element containing more subskills than that of airbending. Whether it's healing, spiritbending, bloodbending, metalbending, lavabending or just shooting lightning out of your fingertips, there are a lot of flashy abilities that come with all the other elements. By comparison, airbending not only has fewer subskills, but the ones it does have (spiritual projection and unassisted flight) are exclusive to extremely few individuals. If you were just a typical airbender, you probably couldn't do all that special stuff.
But that's exactly the reason why airbending should be appealing. All of the subskills require unique training that, for most of the history of the world of Avatar, came exclusively to very few individuals. The secrets of lightningbending were closely guarded in the time of Kyoshi and even by Aang's era, only a select few members of the Fire Nation royal family ever learned it. Combustionbending seemed to be both rarer and more dangerous, with Combustion Man losing two of his limbs before he even learns to control the ability.
The same general trend holds true for the other subskills. While lightningbending and metalbending become far more prolific in the time of The Legend of Korra, Bolin's failure to master the earthbending subskill shows that it's just not for everyone. While the focus of the shows, comics and novels are most often the world's greatest benders of their respective eras, the average Joe Schmo just doesn't get access to quite so fantastical of abilities. But what do the airbenders get?
Their every moment becomes effortless; assisted by the air around them as they run faster, leap higher and never suffer the dangers of great heights. Even to average airbenders, the world becomes your playground, and the fruits of the talents the bending art offers prove far more immediately available than those of the other styles. Even the hardworking prodigy Katara took until the second season of The Last Airbender before she could ride atop water and it's only at the highest levels that firebenders become capable of anything resembling flight.
But airbenders practically start out flying. The subskill of unassisted flight is hardly a loss for the majority of benders who never attain it -- almost all come equipped with a handy glider staff that functionally allows them to fly anyway. And such amplifications of mobility aren't just useful for running away. If you think airbenders are useless in a fight then you didn't pay much attention to either series.
Zaheer manages to become one of the deadliest benders alive after only possessing airbending for a few weeks. In his hands, he unleashes deadly techniques like breathbending that show just how much most airbenders hold back when they're fighting. Gusts of wind are the most efficient way to diffuse a fight without escalation, and whipping a tornado up beneath your opponent and tossing them around is one of the surest ways to control a fight. Perhaps even better, Aang's mastery of airbending allowed him to extinguish fire, throw stone and manipulate clouds and water even before he mastered those elements directly.
But in the end, it's not even about fights. In just day-to-day life the ease of movement and the whimsy of flight would prove far more valuable than any amount of fire you can throw. More powerful abilities may come in handy during world-saving adventures, but those just don't happen every day. Much like the monks who wield it, airbending may just be content to quietly be the best part of Avatar.