@Peter sir,
Even though both were great generals,both have their fair share of faults and the rise of Napoleon from down to his position contrary to the royal blood line of Caesar ,is more inspirational.
I will choose Caesar,due to the following reasons:
1 Napoleon studied and held Caesar in a very high regard.He studied his tactics ,how he administered ,how he motivated his soldiers etc etc ,so we can safely say that Caesar was the "guru" of Napoleon in many ways.And since there is a saying "chela" kitna bhi bada ho jaye "guru" "guru" hi rehta hai.
2 Caesar was a great learner,he was good at learning from his mistakes,and not repeating them.Caesar in his career made the mistake by not crushing the Pompeians, before becoming involved in the Alexandrian War.Napoleon who had studied Caesar in great detail repeated the same mistake by failing to conclude his campaign in Spain ,before embarking on the disastrous Russian invasion of 1812.It is one thing to make a mistake,it is other to repeat it ,when example has been set before you.
3 Caesar never faced any major failure or loss,if he would have, not been assassinated,that to because of treachery behind his back.He would have gone ahead ,to win many more conquest. Where as Napoleon had number of failures,he failed in his invasion of Russia,when his forces were defeated at Leipzig,and he was forced to exile in the island of Elba.In the battle of Waterloo ,where Napoleon was eventually decisively beaten and ousted from power.Which led to his captivity ,until his death.
4 Napoleon army had advantage over most of his adversaries,there is no comparison between artillery and muskets versus bows, arrows and sabres which most of his adversaries were equipped with.Where as Caesar had to fight swords against swords,spears against spears.
5 Caesar was cunning,shrewd and a great thinker,his ability to take quick decision ,adapting to situation and the craft of making his moves like a chess player makes him a greater general.While Napoleon studied and made himself ,Caesar was born and naturally gifted with a sharp mind,which was the main reason behind his rise as a great general.He knew that there is no need of fighting ,when you can win over adversaries by the dagger of sweet talk.