Why Garry Kasparov of course, the other two are dead.
Which player is the best?

No, I meant of all time.
That makes it quite difficult to answer without the ability to see into the future.

Fischer. There has never been anything like him. He took down the soviet chess machine singlehandedly. He absolutely dominated his peers. You can fit the number of people Fischer lost to (as a professional) in a single paragraph.
He was the chosen one.

I believe that this question is extremely difficult - if not impossible - to answer, for a number of reasons.
Firstly, as far as ratings are concerned, FIDE did not adopt the Elo system until as late as 1970, so the ratings of many outstanding players like Steinetz, Lasker, Capa and Alekhine - to name but a few - can only be theoritised.
Additionally, there's the question of tactics vs. strategy vs. positional play: which is more important, and who best represents (or represented) these three aspects.
Many fine claims can be put forth concerning a number of outstanding players, but in the end, it's all speculation.
Fischer. There has never been anything like him. He took down the soviet chess machine singlehandedly. He absolutely dominated his peers. You can fit the number of people Fischer lost to (as a professional) in a single paragraph.
He was the chosen one.
Nobody will deny that Fischer was one of the greats, but his triumphs over a number of Soviet players was not the reason, or even a reason.
For one thing, there is no "Soviet chess machine," except in the minds of propagandists. Soviet players, like all players, had their own styles. Fischer's great popularity in the U.S. had nothing to do with his chess ability per se, but with the childish Cold War propaganda that was being waged on both sides.The fact is that the American public at large adopted chess only as a passing fad, like so many other things.
Another point is that Fischer's greatness lay in his play against a variety of strong players from a variety of backgrounds.
Which chess player do you think is the best out of these three?
Garry Kasparov or Robert Fischer or Jose Capablanca?