They only placed him at number two, 
but we’ll bump the late Heath Ledger’s posthumous performance up a notch for his unparalleled on-screen lunacy. Never has a sociopath been portrayed with such conviction that the audience is left with no empathy. Admit it, the only reason you were sad to see him die was because you’d never see such a perfectly insane character again. Shout out to Kevin Spacey as John Doe (Se7en), but Ledger raised the bar.

Source: complex.com