Back on topic though; chicken sammiches, my opinions. Hmmm....
I will say as a rule that breast fillets are better than chicken patties, the kind that are shredded and formed. Having said that though, I will confess that BK's original chicken sandwich, which is one of the latter kind, is one of my guilty pleasures, when it's made fresh. I'm not recommending it, it's just a weird thing that I personally like.
For "real" chicken sandwiches though, hmmm. It's kind of hard for me to decide, because It just really seems to me that 90% of all the chicken sandwiches out there are indistinguishable from each other, no matter who makes them: "standard fast food chicken breast sandwich" (SFFCBS). And the ones that do stand out, that I liked, aren't around anymore.
I really really liked BK's "tendercrisp" and "tendergrill" chicken sandwiches, they were truly different from anything else out there. But they got rid of both, replacing them with SFFCBS.
McDonalds always had SFFCBS, they just change the names once a decade or so. The newest one has "buttermilk" in the title, but I honestly couldn't tell the difference. A few years back McD's HAD a "southern-style chicken sandwich" which WAS a little different! Got rid of it, though.
It doesn't help that both BK and McD, and everyone else, are on this kick where they all wanna use brioche buns for their chicken now. I mean brioche is okay as a bread, but it toasts too "hard"; the chicken and garnish just wants to slip right out the other side of the bun when you take a bite. Especially grilled chicken, it's so slippery as it is. I have to like hold the sandwich all weird to trap the chicken inside while eating it. It makes those sandwiches irritating to eat.
I don't eat at Wendy's any more at all, but when I did, it was SFFCBS so meh.
Chick Fil A's sandwiches are actually different, I'll give them that; but aside from the moral thing, I never really was a huge fan because their allegedly fried chicken sandwich isn't crispy at all, wth? Was always weirded out by people gushing over them.
When I was very little, KFC actually had an original recipe chicken sandwich, which I liked back then. They gave it up a long time ago, though; except for those silly little chicken-strip sliders they don't really do sandwiches anymore.