Depends how you wanna do, bro.
Nice and simple: A long stem red rose.
Something more interesting: A long stem red rose followed by a small cute mystery gift box (with whatever you wanna put in there, diamond ring, bracelet, necklace, earring, gem, but doesn't have to be expensive).
Even more interesting: The above plus a liminousine to pick her up, or you drive a Ferrari.
If you wanna rock her world: The above plus a new car for her, a new house for her, and $100,000 savings account for her. If you're really planning to excute this, let me know. It was my idea, I want at least 5% of the money.
But it really also depends on what type of girl she is and your relationship. I mean, if you want fun, you can just get one of those carts in the airport and make her sit on it (on top of the luggage of course) and rider her around. And probably also get some of those party stuff (that you throw up in the air) and welcome her aboard. That's childish, but it's fun. Are up a wacko guy?
Or you can just be cool. Walk up to her, give her your elbow and draw her along with you.

Naah, you don't look that type.
I'm tired... but you get the point.