best response to Sicilian?

Your going to get a mix bag of answers because there are so many anti-Sicilians, mainline/open game plans like opposite castling in the Yugoslav, Rozin and English Attacks, and lastly transpositions.

Generally at our level, an anti-Sicilian is best so may be check out the Closed Sicilian or Alapin, see which one you like better and stick with it.

I don't understand the point of playing 1.e4 and avoiding the Open Sicilian.

indeed @ Dzindo07. I agree with you but not many players have the same resolve (as us) when playing the Sicilian. Many players play anti-Sicilians in the beginning to avoid Mainline theory until they have enough experience. As an analogy, I played the French Tarrasch for many years before switching to playing Mainline (Nc3) play against the French.

@3

Theoreticians like GM Sveshnikov have argued that the open Sicilian trades a white central pawn d4 for a black wing pawn c5, which gives black a static endgame advantage.
GM Sveshnikov consequently played the Alapin 2 c3 which he thought more correct.
https://www.chessgames.com/perl/chessgame?gid=1140426

https://www.chessgames.com/perl/chessgame?gid=1070874 

From a practical point of view anti-Sicilians like 2 c3 or 2 Nc3 or 3 c3 or 3 Bb5 avoid the theoretical lines of sometimes 27+ moves deep of the Open Sicilian: Najdorf, Sveshnikov, Dragon... Smyslov and Spassky preferred 2 Nc3
https://www.chessgames.com/perl/chessgame?gid=1318001 
https://www.chessgames.com/perl/chessgame?gid=1049394 

If you really like an open Sicilian, then the classical lines with Be2, O-O, f4, Kh1 are least theoretical.

Khada khada fookda magazine si

At the beginning while learning, it makes a lot of sense to pick a response that narrows the opening tree so you accumulate experience in 1 structure faster and have more tome for endgame study. To me that means Alapin, Morra and closed are the big 3 possibilities.

I don't understand the point of playing 1.e4 period!

1.b4, Best by Test!

It makes more sense to widen the scope and get acquainted with more tactical patterns and structures.

I agree .... but one at a time! (Someone once asked David Hilbert how he worked in so many different areas. His response was "One at a time''.)  - Bill

The Open Sicilian is arguably white's best try (and debatably the most fun!). Though it's also a huge amount of work, if you want to play it properly.

Some players would rather steer down a less theoretical sideline, just to limit the amount of studying required. There are only so many hours in a day ...

2. c3) the Alapin variation https://www.chess.com/openings/Sicilian-Defense-Alapin-Variation

I believe it's best to go into the open sicilian, something like this (though there are quite a few other options for Black even at move 2):

From here, against most sicilians you can go for a setup similar to the yugoslav attack in the dragon:

The point of f3 is to prevent Ng4 trading the bishop, other than that the rest should make reasonable sense. While I don't expect you to see this exact line too often anyways, again this setup is pretty good, at least playable, against just about every sicilian. The idea is pretty simple- throw pawns at their king.