Who was the greatest chess master of all time?

Who was the greatest chess master of all time? Kasparov? Fischer? Karpov? or will Magnus overtake them all? Please comment and give your opinion.

So hard... I admire several chess masters for their different play when playing chess. I would probably choose Kasparov.

this is hard,Kasparov was very good in his time...I would like to see Magnus vs Kasparov at their peaks

Greatest chess master? I think Fischer for his work ethic, Capablanca for his skill, Lasker for his developments and knowledge.

Magnus.

The best chess master of all time in terms of rating is Magnus Carlsen, but Kasparov maintained a slightly lower rating for a longer period. 

Greatness isn't just a measure of skill though. For many, Fischer is the greatest ever because of his inspirational play on the way to the World title against Taimanov, Larsen, Petrosian, and Spassky. 

I still prefer Kasparov as the greatest of all time. His tournament record, his consistent domination for about 20 years, and his matches against perhaps the second greatest player of all time, Karpov, have given chess a much greater treasure than Fischer's few games. 

Tough question... How to compare masters of different periods?? Morphy? Steinitz? Lasker? Botvinik? Fischer? Kasparov? Great players , great chess... Play on and discover the beauty of this great game!!!