I have a top five for war leaders:
1) Napoleon Bonaparte (The Napoleonic Wars): A young french general who seized control of his homeland and built one of the most powerful empires on the planet. That alone is enough to make the list, but Napoleon went further, revolutionizing warfare as he went. Admittedly he suffered the fate of many overly ambitious warmongers, but that only serves to elevate him in my eyes, because ambition is always a quality to be respected.
2) George S. Patton/Erwin Rommel (World War 2): A very close second and tie. Two very brilliant and daring officers who could easily be said to be nemeses. Both were unrelenting in combat and brutally efficient.
3) Ulysses S. Grant/Robert E. Lee (The American Civil War): Again, two mortal nemeses. Lee was a great war leader because he kept the South's fledgling confederate army together in the face of insurmountable odds. ultimately, he was defeated by the total lack of resources that the Confederacy could field. The sheer fact that he kept the war going as long as he did was remarkable. Grant didn't have to take the long chances that Lee did, so he wasn't as brilliant, but he was deadly efficient. Grant didn't care about battles, losses, or politics, he cared about winning. He ground the Southern military into the dust and broke the back of the Confederate war machine. Despite the amazing gap in style between these men they really measure up quite well to each other taking a spot beside each other on the list.
(Yes, there are only three spots for five people, but I couldn't really choose between the latter four)