Macbeth: a hero?

[ale]

I've been trying to decide why Macbeth is a tragic hero. He is an evil murderer who does whatever is necessary to achieve and cling to power. He lacks Othello's nobility and Hamlet's wit. Should his guilty conscience arouse our sympathy?
Personally, I find many similarities between Macbeth and Richard III. Do you think they are heroes, villains, or hero-villains?

[gdog2112]

I have to write an essay and give my view about how "MacBeth cannot be consdered a tragic hero"