Lady Macbeth reminds me, in a lot of ways, of Bellatrix Lestrange from J.K. Rowling's Harry Potter series. They are both cunning and powerful women who are primarily driven by twisted love and ambition. Lady Macbeth will do and sacrifice anything to put her husband in power. She is willing to commit murder and other acts of violence for the sake of ambition. She is passionately in love with her husband, but she sees his gentle conscience as a weakness that she must overcome in order to make Macbeth the king of Scotland. At one point, she tells Macbeth that she would be willing to dash out the brains of her own infant child if it could gain them more power. Bellatrix Black Lestrange serves the Dark Lord Voldemort for several reasons. She is in love with him, in the strangest and most twisted way possible. Furthermore, she desires power, which she thinks that Voldemort has and deserves. Through her cruel violence, she becomes one of his most trusted Death Eaters.
They are both power-hungry and ruthless--traits that make them into evil figures. They are both boldly and grotesquely sexual characters. Bellatrix is a witch, and Lady Macbeth is alluded to being connected with witches and other superstition. Plus, they are both anti-mother figures. They are both married, but neither of them have living children--and in fact, seem to be vehemently anti-children.
Really, any villain could work -- especially if they do wicked things in pursuit of power.
I think that Iago from Othello could be compared to Macbeth. They both want to get power that really does not and should not belong to them. They both betray their superiors -- people who trusted them.
The two aren't exactly the same, but they do both let their desire for power make them do evil things.