Ranking all responses to e4

20) f5
It gives up a pawn and weakens the king for no compensation
19) f6
Hinders black’s own development and weakens the king.
18) Na6
The knight serves no purpose and you’re giving up the center.
17) b5
Gives up a free pawn, only justification is c6 and d5 with tempo.
16) g5
g4 is the worst move for white, does this need more explanation?
15) h5
Does nothing but weaken the kingside and specifically the g5 square.
14) a5
Does nothing but I guess you could attack on the queenside?
13) Nh6
Its only justification is lines where a knight goes to f5 to pressure a pawn on d4.
12) h6
A waiting move that doesn’t weaken much, I guess?
11) a6
The first remotely respectable move as it can be played in French and Sicilian variations.
10) Nc6
Decent, but conceding too much space without compensation.
9) b6
This loses every bit of its venom when there’s no pawn on c4.
8) Nf6
Good for people that like flank openings and counterattacking centers.
7) g6
A very good choice, however below the Pirc because it offers less flexibility.
6) d6
A more flexible Modern Defense (g6).
5) d5
This immediately strikes at the center and is a very provocative and ambitious way to play with black. However, it can get dangerous without careful play.
4) e6
The French is very solid and will catch people off guard, however there are many weapons against it and it can get hard to play for black fast.
3) e5
This classical approach is great, however it allows white to call all of the shots.
2) c5
This is a great opening, and you could very well put this at 1, however I believe that white has too many options and wouldn’t you rather play an opening that no one knows how to play against it?
1) c6
The Caro. A highly debated opening that is probably the most endorsed on YouTube of any move. I put this here because in my experience no one knows how to beat it and it is extremely simple to play.
You’re welcome to debate with me in the comments!

As long as the top 4 are e5, c5, c6, and e6, I’m all good with it 👍

My top 5 would be

1. Sicilian

2. Caro

3. E5

4. French

5. Pirc

Honestly, not a terrible list. Nothing is too out of place except Caro-Kann should be shifted down about three slots, and I’d put the Nimzowitsch much higher.

Not a bad list, but the caro kann should be at 4, 5, or 6

Caro Kann deserves a spot at top 4.

I would move the Caro down to 4, but not a bad tier list at all.

Also, your reasoning with the Sicilian is pretty poor- “Wouldn’t you rather play an opening that nobody knows how to play against?” is a terrible way to play chess. In the Sicilian, if white knows what he’s doing, black gets a great game. If white doesn’t know what he’s doing, black gets an even better game. The Sicilian can’t be refuted, which makes it so good. The element of surprise is a poor weapon in chess, because there’s a level where everyone knows how to play against every one of these openings. The real way to work around this boundary and adopt an opening where the initiating side is good in every line.

I guess, I was thinking more about club level and thinking about the fact that there are around 10-15 responses to e4 c5 as well

Fair, but most of the 10-15 responses are dubious. a3, h3, b3, g3, all are poor. The only decent lines a Sicilian player has to know are, the Open Sicilian, the Closed Sicilian, the Smith-Morra (probably the most important one to learn how to play against tbh it’s really poisoned), the Grand Prix Attack, maybe the Wing Gambit, and maybe the new line with Nc3 and Bb5 (still not hard to play against though). Most of these are easy to learn. The Sicilian is adaptable. Of course, the Najdorf is theory-packed, but if you play even the Classical, you don’t really have to learn too much stuff.

The best are e5 and c5, the Sicilian. They both control the central d4 square, disallowing white a large centre.

e5 is the most solid, equalising move, as it imitates white's development.

c5 is the most ambitious, aggressive move. It controls the centre from the flank, preserving black's central pawns and creating an asymmetrical, imbalanced position.

This is the same as saying there are 20 responses to 1. e4, so you shouldn't bother with 1. e4, when over half of those responses are not considerably challenging.

Agreed. There are two openings: dynamic openings and drawish openings. The Sicilian is the most dynamic response to e4 and e5 is the most drawish response to e4. Polar opposites, and the most effective at what they do.

but they are challenging, that's the point

Against e4 or the Sicilian?

Not more so than the 10-15 responses to the Caro-Kann.

The sicilian. Maybe there aren't 10 on move 2, but think about all of the variations by move 5, even.

I can think of:

Nf3,

f4,

Nc3,

g3,

a3,

b3,

b4,

c3,

d4

Against a lot of these variations like the Alapin, the Closed Sicilian, Snyder, Mengarini, etc. there are simple plans for black to equalise.

All of which are at worst slightly better for black.