If you are to survive gathering 7 magical orbs, and use them to summon an almighty dragon that can grant you one wish, what would be the most beneficial, non-counter-productive wish to ask? Some might ask for youth, only to find themselves transformed into children; others will ask for immortality, only to realize they will outlast even their own species and planet.
What, then, is a wish one can ask for with literally zero regrets afterwards? I'm here to tell you, after much thought, that the only wish that exists under these circumstances is invincibility. Why? Because not only will you not die—nothing could defeat you, even yourself. The only "regret" of such a wish is the desire to taste defeat once more, something which... isn't that desired, is it?
Are you having bad luck with the opposite sex? Be invincible, and no one will refuse your charm. Are you stressed from studies? Be invincible, and you will not fail any exam. Invincibility, whether physical or in any other field, means that you will always win, always succeed in whatever endeavor, because he who loses even once is in no way invincible, for invincibility is the total, if not eternal, absence of any defeat.
We do not truly know what kind of beings exist beyond the stars, and what kind of powers or technology they possess. Some may claim that no political entity can be so advanced to the point of having an interstellar empire, for example, but they may likely know the same as you and I know—nothing, in that regard. In that case, how can we truly affirm or deny that in the extremely distant future, our far ancestors shall find and interact with beings capable of giving us anything we could ever desire?
I believe that the wish for invincibility is the only wish that is truly beneficial and non-counter-productive. It is a wish that has the potential to improve your life in every way, and it is a wish that does not come with any negative consequences.
It is like saying to a peasant in the Dark Ages that in the future, humans would have the power to obliterate entire countries or cities using weapons of immense power in a matter of minutes or seconds. What would they tell you in response? That only a god is capable of such power. The same reasoning can logically apply here as well, all because none of us know what there will be in the next hundreds, if not thousands, of years.
If someone is to read this article in an age where such a scenario—of having any wish—is possible, remember this: if you want to have the greatest benefit without any backfiring and likely regrets, ask for invincibility, and nothing shall be able to stop you. Should the wish-giver be a "troll" and give you an invincibility that will last, like, 10 seconds, as if you're in a video game—ask for permanent invincibility because such invincibility cannot be halted even by time. The notion of invincibility, in the end, can be applied even if it isn't permanent, and should it be lasted even by a second, it will still be a period where you were invincible.
While we cannot be truly invincible right now (or ever, if wish-giving beings don't exist), we can still "aim" for invincibility, by trying and minimizing our chances of defeat as much as possible. There are two ways to do this: either pick our fights very wisely, or don't try at all. In the end, a successful fighter can also be one that always chooses "easy mode" or any difficulty where they are sure to win. How can you avoid defeat otherwise? Don't play the game, and you won't win or lose, but at least you won't lose.