[UnderseaLcpl]

I don't know if you mean army commanders or commanders of all types but I bet they're all Germans.

Rommel, Manstein and Boelcke are all fine examples. The German U-boat aces alone probably produced more "allied war effort destroyed" per person on their craft than any other ace or commander of any kind.
Let's not forget Michael Wittman and Erich Heartman. And Richtofen, who was a flight commander, (or a hunter squadron commander in German).
And Von Shcleiffen, who beat the crap out of the allies after he was dead.

Of course, that is only considering kill/death ratios. If we consider victory there are no German commanders that fit the bill.

I certainly wouldn't nominate Zhukov for the same reason I wouldn't consider Ulysses Grant as a great commander. Throwing troops at the enemy until they die because you have the most troops isn't really a strategy.