I don't think he was that great, certainly not by the end of his career anyway. He wasn't that evil, at least no more than most monarchs with political ambitions. I wouldn't call him that much of a liberator, to some countries maybe but not to Spain for example.
Comparing him to Hitler directly is insane, he didn't gas people, didn't work them to death in camps, didn't shoot/starve/beat to death large numbers of POWs, didn't start using 10 year olds to defend Paris, didn't have generals shot out of hand for not doing their "duty" to him and so on. To the people of his era, especially the English he was evil, a real Bogey man and therefore considered at the time by some to be the era's equivalent of Hitler, this doesn't mean he does compare to Hitler though.
After all Napoleon actually had some military talent to begin with rather than being a gambling amateur with no talent and even less concept of practical warfare. Just about the only way they compare militarily is their inability to understand or care about logistics and their attempts to control battles from afar. The ridiculous lack of planning and preparation both showed on undertaking the invasion of Russia is quite breathtaking. Oh yes and they both inclined towards arrogance, only Napoleon actually had the talent to back it up.
Oh and Napoleon was French, Corsica belonged to France at the time he was born, that's like saying someone born in the Channel Isles isn't British or on Hawaii isn't American.
He was beaten at Waterloo by the Prussians, not the English.
That would be like saying the Germans in WW2 didn't loose to the Russians, they lost to the Western allies.