Schwartzkopfs envelopment and distruction of a large modern army in such a short time will go down in history as one of the greatest military actions of all time; comparable to D-Day, Shermans March, etc.
Franks, while I respect him tremendously, fought two pi$$-ant enemies with overwhelming force. A 15 year old paintball-battle-fighter could have done as well.
Monty's defeat of Rommel was almost entirely due to enigma intercepts. He knew virtually everything. Hard to lose when you get to see your opponents hand.
Schwartzkopf, I think, merely benefitted from a technological advantage with rather pedestrian tactics. Plus, if you include the months of aerial bombing preceding the ground war, it was hardly either a rapid engagement, nor a terribly large modern army by that time.
Franks too had technological advantages, however his enemies were hardly pissant - the first having defeated the Russians and every would be invader since Alexander; and the second only defeated outside their boundaries in a relatively small invaded area. Moreover, Franks had to accomplish his victories at incredible numerical disadvantage of 'boots on the ground'. His war plans truly achieved force multiplication by creative use of both his technological superiority, speed of operation and inherent flexibility.
I think Robert E. Lee is one of the most underrated generals in history. He certainly had a lot more honor than most of the Union generals (e.g., he specifically forbade any confederate forces from looting or pillaging and made sure civilians were spared harm). Lee was largely responsible for the confederacy winning most of the battles. That is not meant to take anything away from Grant, whom I also think was quite competent.
MacArthur was certainly someone I'd like to have on my team. Eisenhower wasn't too bad, either. Patton seemed to be a charge-the-objective, punch-a-hole-through-'em-where-it-hurts kind of guy, which I admire. We Americans love to fight, remember.
For sheer instinctive strategery, Spartacus sure managed to do a lot with a little. So he has to be ranked very high in my book. if you count him as a general.