As a man who has worked in fast food I'd like to weigh in on this.
McDonalds burgers are terrible. They are poorly made, most in the morning, and thy will be served to you at night. They do make the best chips granted, but that's it. Burger king, the oldest hot product you can buy was made 20 minutes AT THE LATEST ago (10 minute holding time in the heat, 10 minutes in the chute after it was made). More than that, I ate McDonalds all my life and could still eat burger king. I work at burger king for 3 months and I can never go to McDonalds again it is so poor in comparison.
Taco bell isn't even in this country, but KFC is and they do make the best chicken, if chicken is you thing.