In Chess you have 2 ways of indicating how good you are. Your ELO rating(for every game you win you get points) and the world championship.
Viswanathan Anand is the current chess world champion.
Magnus Carlsen is the one with the highest ELO rating.
One of the 2 (probably Anand)
Viswanathan Anand .
Miguel Najdorf is arguably the best Argentine chess player in history.
Gary Kasparov may very well be the best chess player the world will ever see .
Sven Magnus Carlsen
Michael Jordan is considered the worlds best basketball player. He won 6 championships.