White kills back with the knight and black's d pawn is weak. By the way the engine puts white ahead by almost a whole pawn (I don't really think that part is overly important, since it's not winning, but it's worth mentioning as an aside).
Now I ranked all of black's responses to Nf3
I definitely appreciate this comment. Yeah, balancing personal preference and objectivity is always the hardest part of these rankings for me.

White kills back with the knight and black's d pawn is weak. By the way the engine puts white ahead by almost a whole pawn (I don't really think that part is overly important, since it's not winning, but it's worth mentioning as an aside).
Considering engines REALLY hate the KID, White being less than +1.2 in a Positional KID is a win in my book.
It's not just the engines that was an aside. The main point was that black's d pawn becomes weak and is now a defensive liability. And really black's set up as a whole is much more passive than the kid normally is.
This is a much better version of the KID. Even here c6 may at some point be useful, but black isn't wasting time with it until then. Or if you want to keep the bishop pair:
And black can make a queenside fianchetto threatening the e4 pawn, or stick with the more common plays and advance c5 or e5 (I'm assuming you already know this but I'm spelling it out for people reading this also).

It's not just the engines that was an aside. The main point was that black's d pawn becomes weak and is now a defensive liability. And really black's set up as a whole is much more passive than the kid normally is.
This is a much better version of the KID. Even here c6 may at some point be useful, but black isn't wasting time with it until then. Or if you want to keep the bishop pair:
And black can make a queenside fianchetto threatening the e4 pawn, or stick with the more common plays and advance c5 or e5 (I'm assuming you already know this but I'm spelling it out for people reading this also).
6.Ng4 exists here

After 1. Nf3 I love to see it (Nc6) almost as much as the Ross gambit (e5). I always follow it up with 2. d4 --what you call the Chigorin Defense (another garbage opening) and then 3. c4 . I see dxc4 a lot, which is a terrible move because of the crushing d5. I've seen titled players lose a piece to this in bullet games (e.g. Nb4, Qa4+). Even if Black knows enough to not play dxc4, White has a huge advantage in central development. "Black should quickly equalize." Not true. Check it with an engine. White is way better, like +0.6 or more.
I think you need to drop this one down into the teen range.
#7 Black Mustang Defense (Nc6):
Following d4 it becomes Chigorin Defense, which isn’t the worst position in the world for black since white has his knight on f3 instead of c3. Black should quickly equalize. Or else e4 turns it into Nimzowitsch Defense Declined, and I’m totally fine with that.

As someone who has been happily playing 1. Nf3 for decades , 1. .. d5 is the best response IMO, followed by 1 .. Nf6. Those are also your top two, but I have to disagree with your third choice of 1 .. b6 . I would drop it 4 or 5 places and put 1 .. c5 in the third place.
The problem with 1 .. b6 is white should known to play g3 and Bg2, with a fianchetto on the same diagonal. Black is left at best with a bad version of a Queens Indian. If White doesn't know to fianchetto in that situation, it's fine.

I was not able to read the list. But personally, I think Nf6 is the best response to 1.Nf3
There is no "Best" response to 1...Nf3. A lot depends on Black's specific style of play.
1...Nf6, 1...d5, 1...c5, 1...e6, 1...c6, etc are all objectively equally good! All the more reason that these "rank lists" are bull(bleep).
It's just like the defenses to 1.e4. 1...e5, 1...e6, 1...c5, and 1...c6 are all objectively good, and the other 16 moves are weaker to variying degrees.
The whole thread is hogwash!
I understand, but I think you missed the key point. I said personally, I think 1...,Nf6 is the best response. I was giving my opinion. I was not telling anyone what they should or should not play.
I like 1...,Nf6 because the move fits into more openings to keep from being " move ordered" into a defense i may not want to play. I like to wait until white commits a pawn whether d4, c4, or b4 or whatever.
This position leads to a very sharp game for both sides. White can't immediately occupy e4 or d4. Objectively, it may belong lower than 3, but I'm biased cause it's my dynamic style of play.
Either of these should equalize after 1 Nc6. Look at Maximum depth on analysis, and you'll see the engine gives white a very small advantage. I don't really listen to the engine unless it says one side is practically winning; yet here I agree with it. I would prefer white personally, but black does have counter play.
exceptionalfork
So the main things I disagree with are both C moves being as high as they are.
Also, as I posted earlier, g5 is playable. Black actually gets nice compensation for the pawn.