I went through all Sicilian variations of GM Moulthun Ly's Sicilian Defense Tier List, where he ranks the Sicilian variations by quality and amount of theory/difficulty of play.
Quality: I discarded every variation that he regarded worse than 3rd class / mediocre quality in his final ranking (even though I briefly considered the Nimzovich Sicilian)(i.e. I excluded the Nimzo, Godiva, Pin variation, O'Kelly (which he has a video on as a simple Sicilian), Paulsen-Basman, Katalimov).
Difficulty/Theory: I discarded every variation he considers highly difficult (i.e. Sveshnikov, Classical, Scheveningen, Dragon, Najdorf). All remaining openings are already interesting for a club player.
I removed variations that allow major alternatives to the open Sicilian, such as the Rossolimo variation (and therefore more theory to know, e.g. the Kalashnikov variation) and variations where Black is passive (e.g. Kan variation, Hedgehog, HAD).
Only two openings remained (Taimanov Sicilian and Sicilian 4 knights), which I investigated with the help of books/chessable openings courses, video lectures the lichess opening statistics and an engine.
Because I wasn't proceeding systematically from the start, I also analysed/read books/courses on the Classical Sicilian, Sveshnikov Sicilian, (Hyper-) Accelerated Dragon and played all of these openings in at least a few Blitz / Rapid games each to get a feeling for how fun, intuitive and understandable the positions are.
In the end, I chose the Four knights Sicilian for practical reasons (and will probably later switch to the Taimanov, if required at any point).
- There is even less theory (there are only two good options for White, and White has to play very precisely).
- Black has a very simple plan of pressurizing the center with Bb4 or quickly breaking with d5 if allowed. At the same time, most of White's typical ideas against the Sicilian that work in other variations are too slow.
- Black develops quickly and actively. No time "wasted" on moves like a6. If White doesn't react immediately, Black is at least fine or even better.
- The opening scores exceptionally well (more points for Black than White!) in amateur statistics (lichess database). Nobody seems to be prepared for this line.
The one big drawback of the Four Knights Sicilian is its objective value. In some lines, Black never equalizes (this is also acknowledged in FM Plichta's Chessable course on this opening).
When following a well-scoring sideline suggested by FM Hacker, one can even end up by force (playing the best engine moves acc. to SF15 depth 23-30) in a position that is +1.2 for White.
In Molton's Tier list, the quality was ranked the same as variations that went into the excluded tier ("just tricks").
However, these positions have never been reached in amateur games on lichess and only extremely rarely in master games.
Also, the position is complex, with the potential for both sides to go wrong. There is potential counterplay and complication.
It is highly unlikely, that 2000-rated players will find the best way to punish this opening choice (unless they prepare it at home).
And even if they reach a position that is better for them, they would still need to play precisely and convert the advantage (far from easy with our counterplay).
Therefore, I concluded, that it is better for an amateur player to spend time to learn tactics/strategy/endgames rather than to learn more opening theory by playing the Taimanov instead of the Four Knights.