Most Important Chess Players

Who have the most important chess players been in the history of this game? Not the greatest but the most important. 

Pawns are the soul of chess. The importance of positional play. Machine vs man. These are just some of the items that have occurred in our history by men who brought the game to a whole new level. Who is the most important and what was their contribution?

Maurice Ashley.

Easy to name names but alas you cannot say why? Especially since you point out "except for Euwe". You're comment "Every world champion from Steinitz to Fischer" rings hollow.

Most important players?  Philidor has to be up there, along with Morphy, Steinitz, Tarrasch, Tchigorin, Pillsbury, Maroczy, Marshall, Nimzovitch, Bronstein--I'm sure I'm missing more than a few, but that's a start.

Philidor - Understood the importance of pawns.

Greco - His writings served as highly useful tools for spotting opening traps.

Steinitz - Considered the father of positional chess

Nimzovich - Hyper-modern chess

Botvinnik - Soviet school of chess, Beginnings of computer chess, importance of chess training and nutrition

Fischer - Improved tournment conditions, bigger prizes

Obviously others, but these come to mind first.

In all serious the most IMPORTANT chess player is you.

Your own success (whoever you define it) is the own thing that will matter in the end.  now, obviously we can go back to the tried and true. X and is better than Y.

Oh, Ok.  Kasporov and Alekhine.  I love attackers and both chess players managed to defeat positional grinders that were considered practically unstoppable.