Most stories ranging from fairy tales to modern day sci-fi features the victory of good over evil. In such stories the main character is the hero who ultimately defeats the darkness. However in Macbeth the main character is the villain. This concept took English literature to a new level in Shakespeare's time and that level is still being explored today.
Macbeth is also one of the clearest reflections of man's thirst for power. Macbeth was driven mad by the witches' prophecy about his becoming of king to such an extent that he abandoned all that he held dear to fulfill his twisted destiny. These kinds of situations also happen today with people committing treason or murder in order to gain a position of power. With Macbeth Shakespeare manages to allow people to see how ruthless they can become to be in command. This is still relevant today.
Macbeth gives both the entertainment of modern day movies and an insight into our blind, everlasting struggle for power. Such classics are worthy of the title "a timeless classic".