Bit American but I'll play.
Not eaten in most of those and thought A&W was a sub par root beer brand but hey. While I am not opposed to fast food on principle or anything I struggle to want to eat it a lot -- it is invariably the "it's 23:00 and we are only just getting back" or "we are on the road and just need to keep moving" choice, one I know I will not enjoy much at the time and probably not after the fact (I would rather go to a supermarket and make a sandwich or a wrap or something with stuff I get in there). How anybody can do them daily or view them as a treat I will never know. I usually did better with smaller chains or straight diners -- I was in Washington state last so did Ivar's and Dick's which did far better than other things on this, such that I might return once a month or so.
Mcdonalds, Burger King, Subway. I don't even rate them as food. I don't know if it was a Quiznos I tried after Subway had, to put it politely, failed to impress on several countries over multiple continents but it was not much better.
Unlucky fried kitten. Edible I guess but how anybody enjoys it I don't know.
Haven't had a jack in the box in about 14 years at this point. Was edible enough in a completely and utterly bland "this is American fast food" sense.
Krispy Kreme? Aren't they a doughnut shop? If I am after sugary American doughnuts... actually there was another I went to last time that actually had stuff that might have sold in an English bakers. Can't remember the name though (will possibly consult a map as I know where it was). Leave a tray of Krispy Kreme doughnuts around and tell me you will feel bad if they go off and... you won't be feeling bad.
Cinnabon. At one time they were godly. Now I quite like the ones you do at home more, especially if you have some icing sugar on hand to make more sauce.
Dunkin Donuts. Never been there. Walked past one once and it stank of grease and bad/burned coffee, saw in the kitchen and it was about as clean as anything like that ever gets so that says more about how they make their stuff than anything else.
Jersey Mikes. The way some talk them up... I just don't get it. Got a wicked case of the shits afterwards as well, repeated visit repeated the result. Won't be doing that one again. Tasted vaguely acceptable when I did though which means it is light years ahead of subway.
Panera Bread. Actually somewhere to get some half nice bread in the US without having to make it myself (as a general rule sugar does not belong anywhere near bread unless it is a filling (it is a student/poor person thing) and while some still bore something it was toned down enough that filthy UK type could choke it down. How a Frenchman (I have done their small villages where you buy it warm on the daily... I approved) would fare I do not know.
Arbys. Their adverts annoyed me so were downgraded from something that might ward off starvation to just no. Even when their adverts were not annoying me the shots looked like the cheapest and thinnest cold cuts put into bread I would feel bad about giving to pigeons.
Wendys. I think this was the site of the infamous few chillies burger. I was at my grandparents and they eat plainly which is fair enough. I on the other hand eat chillies and curries like they are going out of fashion, and had done for years on the trot at this point. We go to one and I order a chilli burger. Open it up to remove the slice of devil's gonad and see 5 jalapenos in there... it was not enough -- I can't say I have ever been addicted to anything in my life but I think I might be to spicy food (this would have been about week two of not having much spice). Also speaks to the potency of Jersey Mike's if such a thing can reliably upset my constitution. Anyway compared to most on this list... I am not sure what they do to have so many people on comedy sites rag on them so much. Know what you are doing and you might be able to eat well enough here to actually achieve something resembling nutrition.
Five guys. Turns out peanuts and I are not friends any longer which made a visit tricky. Burger was OK I guess, which means as far as massive chain fast food goes it was actually very good.
Dairy Queen. Apparently the home of the thousand mile an hour burger so most people I am likely to be with would object on principle. I don't need to eat during the day (why would I waste money on food when I can be getting other things?) and thus no real chance of me going there, not to mention if it bothered their stomachs then definitely not as they are even better than me.
Taco bell and taco time (some might call it heresy merging the two but eh). Not a patch on a real taco or burrito but actually acceptable. Going by general internet opinions that will be shocking to some but I guess I have my quirks.
I think I went past a chick fil a. The religious weirdo aspect is enough for me to know about it so that might have put a damper on it but the same shopping whatever it was had a nice ice cream shop so when given the choice I went for that instead. That said they are apparently famous for said chicken and when trying something somewhere else that people were comparing to it... that thing tasted about the same as a middle of the road supermarket chicken kiev (breaded or battered thing with some spices in/on it that you chuck in the oven for 40 minutes from the freezer if you can't be arsed to cook that night).
Only know of Hardees/Carl's Juniors because I watched the
company man video on the subject. Don't know if I have even seen one in the wild.
The others I am not sure I have ever heard of other than White Castle is a name of one of the Harold and Kumar films in certain regions.
Worst fast food. In a mall somewhere in Sloten (don't know if it is technically part of Amsterdam but close enough that we went to it by tram) in the Netherlands. The people billed it as middle eastern food but done as fast food. Just no and I really like middle eastern food if you can pick the stuff without tomatoes.