In-n-Out is the only fast-food place that I eat now, and let me tell you why. First, the prices are very reasonable for the fresh food that they provide. I remember my Big Macs never, ever, ever looking like they do in the photographs. But at In-n-Out, you can be sure that your burgers, cheeseburgers, or double-doubles will always, always look as good as they taste! Fresh lettuce, tomatoes, and onions (if you like) make the burgers unbelievably delicious! Plus, the french fries are - gasp - made from fresh potatoes that you can see workers push through cutters right in front of your eyes. No frozen fries here - and somehow they taste just as good as the super-sized ones from the clown.
The menu here is simple, but they also have a secret menu that you can indulge in so it'll make you feel more like an insider (check out their website!). This place serves excellent food, but please, remember that it is still fast-food and hamburgers - hit the joint cautiously. This stuff isn't fat-free and is actually high in calories (understandably so).
A side note: In-n-Out is basically the only fast-food joint that Eric Schlosser, author of Fast Food Nation, endorses due to their good business practices and fair treatment of their employees. Just FYI.