From USA Today:
The food: In an increasingly complicated world, the reason for Chick-fil-A’s success is shockingly simple – they make a tasty fried chicken sandwich. This is especially true and obvious when compared to their main competition, the even-bigger national fast food chains that serve up processed patties of chopped something that tastes vaguely like chicken. Chick-fil-A’s sandwiches look better, as they are breast-shaped rather than unnaturally round, and they definitely taste better, with the breast consistently thick, juicy and served quite hot. It may not be gourmet, but it is as good as a fast food fried chicken sandwich gets.
The main menu category here is “Classics,” and nearly half of those entries are variants on the standard fried chicken breast standard served with pickle slices. It also comes “Spicy,” with spicy breading; “Deluxe,” adding lettuce, tomato and American cheese; and “Spicy Deluxe,” with lettuce, tomato and jalapeño Jack cheese. What makes all these options taste better than competitors is the fact that they use a piece of actual breast, fry it in pure peanut oil (the longtime Southern standard for fried chicken but considerably more expensive than alternatives), and serve it on a bun that is not only quite tasty relative to most fast food hamburger rolls, but is buttered, packing in extra flavor (and calories — a wheat bun is available on request).