(FORTUNE Magazine) – Airports are no longer just places to catch planes. Between the shopping, spa treatments, and kiddie museums, who needs to be on the 11:30 A.M. to Dallas? As delays become more prevalent, airports have found a formula to milk their captive audience--from personal shoppers in Chicago to fresh sushi in Miami. In fact, nonairborne extras such as concessions and rental cars are responsible for more than 60% of revenues for the top 20 airports. Below, we've constructed what we think would be the perfect--and most profitable--airport. Now if the airlines could just get their acts together.

AUTO SHOP O'Hare offers premium valet-parking services--such as a personal shopper. Customers fax a list of items, and purchases are waiting in their car when they return.

TOUCHDOWN! Landing in New York City's J.F.K. makes Producers tickets look like a bargain. The airport takes in $178 million charging for services other cities provide for free.The money helps pay for J.F.K.'s pricey "sealane" runway over Jamaica Bay.

PLUG AND PLAY Denver's terminals let airlines outsource services--everything from electricity to jet bridges. For a price, that is.

HARD DRIVE Disney World makes Orlando a top tourist destination, but the airport does its part by keeping airfares down. Its secret? Offsetting ticket prices with car rental revenue. After all, half of incoming passengers rent one.

CHEAP THRILLS Miami's concessions cater to the budget consumer--many specialize in goods under $10. And travelers with long layovers can flock to the 262-room hotel.