I only have experience with McDonald's in Western Europe, and here the food is not good. The pattys seem like the meat was thoroughly grinded to a smooth paste. The bread doesn't have any flavour, and because it's in a closed package with the rest it becomes soaked and soft from the steam. The worst part is the cheese (if you can call it that -- it doesn't look or taste like cheese at all). The fries are okayish. On the rare occasion that I'm with a group of people who want to eat something at McDonalds, I usually take a salad with the sauce in a separate package, because even the salad sauce doesn't taste good.
This was surprising to me. You can make a much better burger than McDonalds in 10 minutes with standard equipment. Just take some minced meat, form it into a flat cylinder, rub some olive oil salt and pepper, cook it in a frying pan, after you turned it around add (real) cheese on top and cook the other side, slice a bread in two and roast it a little in the same pan, and stack up the burger with some lettuce, tomato and some mustard and/or ketchup. Why can't a company whose primary purpose is to make burgers not make a burger half as good? It's not like the ingredients here are more expensive. Or do people really prefer McD's burgers?
UPDATE: And I didn't like it in the US either.