Denny's? They still exist?
I remember when they had a Grand Slam breakfast for $5, but it overall was horrible, and a few still exist. Long ago I ordered a plate of fried vegetables and seriously they brought me some vegall dripping in grease. The waiter to his credit said "This is probably not what you wanted."
I once had a chicken sandwich from Hardees that was raw inside, barely cooked, took it back of course. Didn't go back.
McDs for all the criticism they take at least has some standards. I will say the Big Mac in France is mostly lettuce, maybe half the beef we get here, and expensive of course.
I also tried one in London once, I could not understand the lady taking my order, and vice versa.
General rule, avoid fast food places, and cheap steak places like Longhorn, avoid Applbies, TGIF, whatever else.