@alexmilman
I would propose that we try to limit the discussion at least to independent commanders, if not supreme commanders/commanders of main armies, on the grounds that their efforts produce the most important results, and that the criteria for best be their ability to produce results in the context of their situation.
This is of course a valid approach but it still leaves the PR factor. Some personages of that rank got more or it than another just by the cultural/political/religious reasons. Just a few examples:
"Everybody" knows that Turenne was a great general: besides the fact that he really was one, an important thing is that he was French and European culture was greatly influenced by the French with the resulting promotion of everything French. However, his contemporary, Montecuccoli, is much less known even if he won the 1st field battle against the Ottomans and in 1673 completely outmaneuvered Turenne.
Gustav Adolph was a great military reformer and a capable tactician but his reputation was blown out of proportion by the Protestant writers (German and British) while Wallenstein was routinely vilified, mostly because he was on the "wrong side". Needless to say that behavior of GA's troops in Germany was not better than one of their opponents and that nobody (including his own Chancellor) could say for sure what are his political goals.
For a while Charles XII was everybody's darling (why the Dutch had been so happy about his victory at Narva is anybody's guess) and ended up as a somewhat romantic figure.
On one extreme ends of the spectrum, Alexander the Great achieved extraordinary results despite remarkable inferiority of strength.
This issue of a disparity had been questioned at least since the time of Delbruck and it seems more or less accepted that at Granicus he had at least 30,000 infantry and 5,000 cavalry against 10,000 cavalry while estimates of the Persian force are varying wildly: 5,000–20,000 Greek
hoplite and 10,000–20,000
cavalry. So in the worst (for him) case scenario he had almost a parity (with a big advantage in a disciplined heavy infantry) while in the best case he had almost 2:1 numeric advantage. However, the "tradition" supports an idea of the countless "barbarian" armies (of course the Persian empire with its ancient culture ended up on a barbarian side just because the history was written by the Greeks

).
I'd say that the Mongols were a better example of the "extreme case".
On the other end, the fact that England, a small state in comparison to France, was able to defy and even humiliate its larger, more powerful rival in the Edwardian phase in the Hundred Years War reflects very poorly on the generalship of Philip VI and John II.
Well, AFAIK, military ineptitude of these kings never was in doubt but you also should keep in mind that England started the 100YW with a much better military system against which the French simply did not have a remedy.
Just so I'm not misunderstood, inferiority of forces is never a good thing; the duty of the statesman and the general is to set themselves up for the greatest success, and the best way to do this is by employing the greatest possible force. Inferiority in this respect can only be a necessary evil in war, and can only be justified by success. Nevertheless, for us as analysts, we recognize that certain talents are best displayed in adversity of one kind or another, and great generals enable their states to win greater successes than they otherwise would, allowing small states to punch above their weight and large ones to contemplate supremacy.
As far as I can tell, this "inferiority of forces" thing is a part of the European cultural tradition and I'm not sure that it works the same way elsewhere. Anyway, we do know that to make his successes more spectacular for the general public Napoleon routinely played with the numbers for both sides to show that he was winning with inferior forces even if his own principle was "God is on the side of the big battalions".
OTOH, sometimes inferiority of the numbers can't be helped as was the case with Mongolian conquest of the Northern China. Then, of course, we can talk about the talents of generals who managed to compensate for this problem by a greater mobility, better discipline, etc. But then, again, the issue is not going to be simple because Genghis was a great military reformer, a great strategist but not a very good field general (at the beginning of his career he was routinely beaten in the battles). On a 2nd level everybody knows Subotai (mostly because of his role in European campaign) but Mukhali (a person who was officially Genghis' #2 with a
hereditary vice-royal title) is much less known because he was conquering China.