The best should be "happiness after pain."
This fruit's effect causes the mind to become exceptionally clear, the perception of things to become much sharper, and it even slightly approaches the state of enlightenment.
Of course, there is still a big difference from a complete state of enlightenment.
But it's quite substantial nonetheless.
Although the "bone-piercing pain" effect also brings clarity, its excessive bitterness can impede mental clarity, so it's considered second-rate.
Next comes "happiness like sunshine." This effect is basically the same as that of the Happy Sunflower, only enhanced and one-time because it's contained within the fruit.
For sword cultivators and demonic cultivators who have a lot of malevolence and killing intent, it's a good method of relief.
The last is "clouds that follow the sunshine."