Here's your Forbes Daily Briefing for Monday, June 23rd.

Today on Forbes, the one luxury these billionaires say they can't live without.

Billionaires have been known to indulge in just about every luxury imaginable.

Picasso's, diamonds, private concerts by A-list pop stars, super yachts with cinemas, spas, and submarines,

trips to space. Because there's almost nothing a three-coma fortune can't buy,

billionaires are often accustomed to owning the best of the best of whatever they want.

But Forbes wanted to know what indulgence they view is absolutely essential.

So this winter, we surveyed many of the world's billionaires on the one luxury they can't

live without, and 40 billionaires responded.

The most common answer by far was a private jet, which a dozen respondents chose.

After that, three listed their phones. A couple shoutouts apiece went to

prestige cars, second homes, and yes, air conditioning. And two listed their wives, Charles Koch,

the chairman of Coke, who's estimated net worth is $67.5 billion, wrote, quote, Liz for 57 years.

Stephen Smith, founder of Canada's first national financial and whose net worth is $6 billion,

said hell-skiing.

One anonymous respondent, fittingly wrote, quote, privacy.

Though 12 is a small sample, hundreds of other billionaires own private jets,

so why do they put such a high premium on their planes? In most cases, it's about saving time.

The process of traveling to a commercial airport, passing through security, boarding, and

taxiing typically takes several hours, even without delays.

A private jet, meanwhile, can be ready in minutes.

Not only can those passengers just show up and go, but they also have far more options for where to take off and land.

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