This time I ranked all 20 responses to d4 for black

Feel free to post your opinions and/or rankings. And let me know whether or not I should continue doing these, next with responses to Reti.
IMO it would go like this:

Bottom tier

20. g5 (Borg gambit): Basically a grob but a tempo down, the grob by itself is already a tricks only.

19. f6 (unnamed): The point of this move being.... 
If black wanted to play some sort of mirrored caro kann it is just not going to work. Attempts of symmetry on the kingside and queenside are not going to work because the queen and the king are different pieces. After e4, black can't even play e5 normally because black can not recapture, because of Qh5+. Black can play nc6, which is a transposition to the hammer gambit in the nimzowitsch defense, but if white plays nf3 and bc4 controlling the weakened diagonal and not allowing castling black is just going to have a hard game. 
White can also play 2. nf3 controlling the e5 square, and at this point the best thing black can do is play f5 and play the dutch a tempo down. Why would anyone do that. f6 also deprives the knight on g8 from it's best square

18. Nh6 (unnamed): This defense only works in atomic chess. In normal chess, is just a misplacement of a knight. it does not control any useful square

17. h5 (unnamed): This defense weakens the kingside and does not do anything important for the position.

16. Na6 (australian defense): This defense was played by nakamura against Wang yue. This defense is definitely better than nh6 because in this, at least you are trying to set control on a more important square such as c5, but it allows white to simply play e4 and take over the center.

Low- middle tier

15. a5 (unnamed): This response also allows white to take over the center and does nothing but at least doesn't weaken the kingside like h5, so it's just a wasted move and not a lot more than that.

14. e5 (Englund gambit): This is objectively one of the worst moves you can play against d4, but i let it be on the low-middle tier because at least it has some tricks.

The hartlaub-charlick gambit has some danger if white takes on d6 and isn't careful enough after that, but the lines where white protects the pawn with nf3 instead of exd6 often lead to uncomfortable positions for black.

13. h6 (unnamed): This move also allows white to take over the center but at least it prevents a possible bg5 in the future.

Middle tier: 
12. nc6 (mikenas): the point of this defense is to prepare e5 in the center. after 2. c4 e5 3. d5 black can play bb4+ prior to nce7. Which is why after nc6, the best approach for white is to push d5 followed by e4 and try to build up in the center. After e4, if black plays ng6 white's best move is h4 threatening to chase the knight and almost forcing black to play move like h5

11. c5 (Old benoni): The old benoni is better than all the other responses below it. it's still not that great. After d5, black can transpose into other lines of the benoni if white plays c4 against for example: 2.d6, 2.e6 or 2.nf6. However, white's best approach to those three responses is actually not to play 3.c4 but rather play 3.nc3 preparing for e4, which is why it's not so great for black.

10. a6 (st george's): This defense usually aims to play b5, it can also (sometimes, depending a lot on white's moves) transpose into a line from the modern defense. unlike other moves (1. h6, 1. a5, 1. h5) This move actually has a purpose and does not create a weakness compared to 1. a5 and 1. h5. 
Usually an idea of white to counter b5 is g3 followed by Bg2, however black has some interesting ideas after 1. d4 a6 2. g3 e6 3. bg2 c5 and after 4. d5, exd5 5. bxd5 Nf6 attacking the bishop

9. b5 (Polish defense): Black plays b5, looking for a fianchetto on the light squared bishop and also controlling the c4 square. White can still play c4, which is kind of a reversed birmingham gambit where white has already played d4, but white's best approach is to play e4 controlling the center. black after e4 can play either bb7 or a6, being bb7 more common and kind of a reversed polish but with the option of white to play bd3 without blocking the d-pawn
White can also play 2. Qd3 which is a reversed german defense. 
Overall b5 is not the strongest response by black but not a bad one.

upper-middle tier: 
8. b6 (English defense): An ok weapon that often arrives to e6 b6 positions. White's best move is e4, transposing into the owen's defense. It can Transpose into some Queen's indian positions if white doesn't immediately play e4 and black decides to prevent it with nf6.

7. g6 (modern defense): Not a lot to say here. White can play e4 transposing into a normal modern defense, or c4 which either it's still a modern defense or transposes into a KID/grunfeld if black plays nf6.

6. d6 (OID/KID/English rat/Pirc): the move d6 usually looks to transpose to an Old indian defense/King's indian defense. White is allowed to play e4, which transposes into a pirc defense so you have to be familiar with this opening if you play this.
the situation where d6 is stronger is when white plays 2. c4 which allows black to play 2.e5 entering into an english rat defense, a strong defense if you ask me. 
5. c6 (Slav/caro kann): this move is transpositional. If white plays c4, nf3, g3, black plays d5 aiming for a slav setup. If white plays e4, it's a transposition to a caro kann. If white tries to play the accelerated london with 2. bf4, black can answer with 2. Qb6 attacking the b2 pawn. 
4. f5 (dutch): In this defense black usually tries to develop the pieces from the kingside quickly, take a control on the e4 square and also play b6-bb7 if possible. However, black needs to be flexible enough, because the setups (Classical, modern, stonewall, bb4) should be played depending on what white plays. You can not always play the stonewall for example against every white's setup. In the dutch, white's most played response at master level is 2. g3 because it controls the h1-a8 diagonal before black does. 
If black plays 1. f5, black needs to learn what to do against aggressive responses such as 2. e4 (staunton), 2. g4 (Krejcik) or 2. Bg5 (Hopton attack). If black wants to avoid these responses, black can play 1. e6 followed by f5 but also assuming the possibility of a french transposition if white plays 2. e4 or 2. nc3 
Top tier responses:
3. e6 (Horwitz): This is a great transpositional weapon. It can transpose into a dutch, QGD, english/owen defense, french defense, indian defenses with e6, benoni, catalan, etc. Black usually waits white to show their plan before they do. Black can also play the kangaroo defense against 2. c4. possibilities in this opening are a lot. This is a very flexible move.
2. d5 (Queen's pawn game): Not a lot to say here. Opens up the diagonal for the LS bishop and puts a pawn in the center controlling the e4 square, solid response by black.
1. Nf6 (Indian game): Controls the e4 square with a knight rather than a pawn. Most played response to d4 at masters level, developing a piece. You can play the indian defense that suits more you style: KID, Grunfeld, nimzo/queen's indian, bogo indian, dzindzi indian, OID, benoni, benko, etc. A very flexible move.