Randy's Donuts is a classic, known both for its iconic sign as well as for its impeccable donuts. It's located just off the 405 north of LAX---the giant donut is clearly visible from the highway.
A donut makes a perfect post-flight salve. I kicked off this visit to LA with a devil's food donut and mocha iced coffee. The donut actually has icing on the other side---I was in too much of a hurry to enjoy it to flip it over for the photo. The iced coffee was a great complement. They made the rest of the day more enjoyable.