I just read a five part sequence (Thanks Scott) by Ada Palmer on Machiavelli that is extremely well-written and very effective. Part one gives the context of Machiavelli's work, and explains how important Florence was to him and why that continues to matter to us. Palmer doesn't spend much virtual ink actually justifying Machiavelli as a hero, rather she explains the dire situation Florence was in, and how and why that mattered to Machiavelli.
She ends the first part of the series by giving him as great an accolade as she can imagine. You know the parlor game in which you imagine sending a message back to some past historical figure on their deathbed (not in order to change history, but to tell them that they made a difference)? She would take that opportunity to reassure Machiavelli that his beloved Florence continues to flourish and is held in such high esteem that (by the UNESCO World Heritage Convention) "it is on the list of places [that] all the powers of the Earth have agreed to protect with all their resources."
In the next three or four parts, Palmer explains and justifies her claim that Machiavelli invented modern Political Science and the modern approach to ethics. It's well worth reading.