Definitely not Elroch
@Zborg, you are such a flirt.
Glad to see an old dog can learn new tricks, @Elroch. Merry Christmas, and Happy Holidays to you too.
@Kingpatzer has respectfully requested his thread back. Let's give it to him. I'm game.
To wit, Karpov, Kasparov, GM John Nunn, and even GM Ken Rogoff have all had (or are having) outstanding "careers," whether chess or otherwise.
Carlsen's (chess) career has yet to fully unfold, so he doesn't count, yet. Sorry, no awards for WCC "in waiting."
Can this question even be approached effectively, let alone answered?
@Kingpatzer has laid down the parameters. Have at It Folks!
Paul Keres, - not only of his actual career but also the way he got into it ... In the early 1930's there was no chess culture one could talk about in Estonia (apart from the baltic-german one). The only theoretical works that were accessible, were pre-Stenitz German chess books. I can not think of any highly rated chess players, who had to do so much work just to get into properly playing chess. (not only chess literature was scarce, but Keres didn't have many players to even play with, so his chess matured mostly by playing correspondence chess while in high school - perhaps 150 games simultaneously). Keres's success in the chess world can not be compared for instance to the Russian players, who had their own school of chess.
Have to take my top off as he is hated and for good reason.
Now i have to say Tal.
I would say Fischer
but next probably Stalin