who is the greatest chess player in the history???

Paul Morphy was the greatest chess player that ever lived. Every student of the game, who has delved into the stories of the past, realizes that no one ever was so far superior to the players of his time, or ever defeated his opponents with such ease, and no one ever offered knight odds to the men who considered themselves his equal.

• As quoted in Lasker's Chess Magazine

Could Kasparov give Karpov knight odds and win?

Anand 

Written at a time when the chess world had not yet seen much of Capablanca, Alekhine, Botvinnik, Tal, Fischer, Karpov, Kasparov, etc.

"... Morphy became to millions ... the greatest chess master of all time. But if we examine Morphy's record and games critically, we cannot justify such extravaganza. And we are compelled to speak of it as the Morphy myth. ... [Of the 55 tournament and match games, few] can by any stretch be called brilliant. ... He could combine as well as anybody, but he also knew under what circumstances combinations were possible - and in that respect he was twenty years ahead of his time. ... [Morphy's] real abilities were hardly able to be tested. ... We do not see sustained masterpieces; rather flashes of genius. The titanic struggles of the kind we see today [Morphy] could not produce because he lacked the opposition. ... Anderssen could attack brilliantly but had an inadequate understanding of its positional basis. Morphy knew not only how to attack but also when - and that is why he won. ... Even if the myth has been destroyed, Morphy remains one of the giants of chess history. ..." - GM Reuben Fine

I'm going to say that if you are better than any of your other opponents so much that they don't catch up for 20 years then that absolutely  justifies such extravaganza.   The Italian army was dreadful in WWII.  The Roman Legions at the start of the empire were simply unmatched by anyone they could take on every other army in the world combined.  Yet 1% of the WW2 Italian army would crush the entire Empire's army in a heartbeat.  When matters.  

The answer to the question of "Who is the goat?" always turns into "Who is my favorite player?"

With that said...My favorite players are:

Capablanca

Petrosian

Karpov

Who do i think is the goat?

Kasparov

And, in the case of Morphy, "when" was, essentally, the primitive chess world of 1857-8.

I love Morphy  Cause he gave a lot of things to the future generation. 

Hikaru nakamura is my favorite

 obviously 

Morphy, Fischer.

I am

Bobby Fischer

Here are my top 5 :

1- Garry Kasparov 

2- Magnus Carlsen 

3- Robert James Fischer

4- Anatoly Karpov

5- Vishy Anand

@chessopera and he was playing amateurs all his life. There was a study done by Chessbase of all his games,  and they determined that he wouldn't even be a GM level by today's standards. It isn't so hard to shine if you're only playing very weaker players most of the time. 

Lawson's Morphy biography indicated that Morphy acquired a few chess books in 1853. Lawson included a report of a Maurian quote:

"... During the two years that we remained at college together, Morphy played a considerable number of games with me at odds gradually diminishing as I improved. ... Mr. Morphy had the following Chess books with him, the only ones, as far as I know that he ever possessed until the New York Chess Congress in 1857. Horwitz and Kling's Chess Studies, which he pronounced a very good and useful book for students, although not free from error; the B. Vols composing the collection of Kieseritzky's La Regence, and Staunton's Chess Tournament. ..."

"... Morphy became to millions ... the greatest chess master of all time. But if we examine Morphy's record and games critically, we cannot justify such extravaganza. And we are compelled to speak of it as the Morphy myth. ... [Of the 55 tournament and match games, few] can by any stretch be called brilliant. ... He could combine as well as anybody, but he also knew under what circumstances combinations were possible - and in that respect he was twenty years ahead of his time. ... [Morphy's] real abilities were hardly able to be tested. ... We do not see sustained masterpieces; rather flashes of genius. The titanic struggles of the kind we see today [Morphy] could not produce because he lacked the opposition. ... Anderssen could attack brilliantly but had an inadequate understanding of its positional basis. Morphy knew not only how to attack but also when - and that is why he won. ... Even if the myth has been destroyed, Morphy remains one of the giants of chess history. ..." - GM Reuben Fine

Fischer

There was no rating system back then. 

If you analysed ten Morphy games at random with an engine, you would be disappointed at the quality of his play. 

Kasparov has also done simuls against 'the best of the rest.' the 'rest' in the mid 1800s, weren't very good at chess relatively speaking. 

"Lasker ... didn't understand positional chess." - another Fischer quote from around the same time as his Morphy comments.
Extended discussions of Morphy have been written in books by GM Franco, GM Beim, GM Ward, GM Marin, GM Bo Hansen, GM McDonald, Garry Kasparov (with Dmitry Plisetsky), and GM Gormally. Anyone see any of them express the view that we should accept Fischer's conclusion about Morphy? There seems to be general agreement that Morphy was, as GM Fine put it, one of the giants of chess history, but that is a long way from saying that he was better than anyone playing today.

Carlsen-2961 Kramnik-2868 Kasparov-2816 Fischer-2775 Anand-2759 Karpov-2698 Capablanca-2664 Tal-2636 Spassky-2619 Smyslov-2618 Botvinnik-2602 Euwe-2547 Alekhine-2547 Petrosian-2543 Lasker-2498 Morphy-2409 Steinitz-2323
https://www.chess.com/article/view/who-was-the-best-world-chess-champion-in-history
"... Morphy became to millions ... the greatest chess master of all time. But if we examine Morphy's record and games critically, we cannot justify such extravaganza. And we are compelled to speak of it as the Morphy myth. ... [Of the 55 tournament and match games, few] can by any stretch be called brilliant. ... He could combine as well as anybody, but he also knew under what circumstances combinations were possible - and in that respect he was twenty years ahead of his time. ... [Morphy's] real abilities were hardly able to be tested. ... We do not see sustained masterpieces; rather flashes of genius. The titanic struggles of the kind we see today [Morphy] could not produce because he lacked the opposition. ... Anderssen could attack brilliantly but had an inadequate understanding of its positional basis. Morphy knew not only how to attack but also when - and that is why he won. ... Even if the myth has been destroyed, Morphy remains one of the giants of chess history. ..." - GM Reuben Fine
It is perhaps worthwhile to keep in mind that, in 1858, the chess world was so amazingly primitive that players still thought tournaments were a pretty neat idea.

"... It was due to [Morphy's] principles of development that he had, in most cases, at the outset a better development than his opponent. As soon, however, as these principles of Morphy's had become the common property of all chess players it was difficult to wrest an advantage in an open game. ... the next problem with which players were confronted ... was to discover principles upon which close positions could be dealt with. To have discovered such principles, deeper and more numerous as they were than those relating to development in open positions, is due to Steinitz. ..." - Richard Reti (1923)