There seems to be an imagined hierarchy with some anime viewers who believe watching subbed anime is better than watching dubbed. I do not agree nor buy into that. Thus, I included this question into the series. This one is obviously only for the anime watchers. The manga focused question will be posted in a few hours.
The question of what is your favourite ability in One Piece can be interpreted in multiple ways. It can be seen as asking broadly for your favourite devil fruit or fighting style. It can also be seen as do you prefer Devil Fruits, fighting abilities or the voice of all things. So for this post I shall answer which I like of the three over all and then specifically which fighting style and which devil fruit I like.