Napoleon (of course, Austerlitz was genius), Hannibal simply because of Cannae, Marcellus for beating Hannibal multiple times after Cannae and for taking Syracuse (he was a better general than Scipio, just Scipio was over-glorified for the siege of Carthage) and Oliver Cromwell for his civil war achievements, making the new model army the basic structure of military today.
A lot of people have said Alexander "the great". I disagree, personally I believe his achievements were over-glorified and generals aspire to be like him simply because they have not studied deep military history and he is famous for his name. All Alexander really did was win a single battle which gave him the entire Persian empire, from there he just made bad decisions, got half his army killed from disease going too far too boldly into India, and leaving no successor causing war and a split in his empire after his death (he would be terrible at CK2).