Variants

Alice chess because playing chess on only 64 squares is boring, at least you have two boards

@Shadow1414 say "None. Chess is the best for Chess."

While this is true, it doesn't mean playing chess variants can't be used for occasional or even regular cross-training.
See https://www.healthline.com/health/fitness/cross-training#what-it-is
Regarding chess read https://en.chessbase.com/post/why-you-need-to-learn-xiangqi-for-playing-better-chess

@RealHuman2 said in #1:

Guys, which Variants do you think are actually good for your standard chess?
Three check and koth (I don’t consider 960 to be one ;) )

I think many variants can be good for your chess. Likely no training on chess variants will help your chess as much as training on chess itself though, but if you enjoy playing them and it still helps your chess somewhat, why not.

As someone playing an excessive number of chess variants, in my experience the most problematic variants are ones that use the same board and pieces, but require you to play very differently, like antichess, because they can potentially mess with your pattern recognition. In contrast, games that look very differently, like shogi, xiangqi, janggi, etc., but have very similar underlying game mechanics can give you new insights and sharpen your calculation without interfering with your chess. And of course chess960 can be very beneficial and can't hurt, because it is just a superset of positions, so it won't interfere with your standard chess thinking.

@RealHuman2 said in #1:

Guys, which Variants do you think are actually good for your standard chess?
Erm..... Atomic, because... uhhh I can boooom the chess board

chess960. Same piece movements, patterns and principles.

Horde is (prob) the hardest chess variant

I would say King Of The Hill is the most similar to standard chess so it (KOTH) kind of helps me play better chess

@IamCoconut said in #15:

Erm..... Atomic, because... uhhh I can boooom the chess board

XDDDDD HAHAHAHA

None really

Select a themed position. There are theme tournaments. That's a good variant too. Who ever said we had to learn chess from the starting position. Many start by pawn storms without pieces. I learn chess with K vs K+P.