The most obvious answer would be to say that Macbeth by William Shakespeare is one of the great works of English literature that genuinely deserves its place as a masterpiece in the literary canon. While that is true on many levels, and the writing is unquestionably outstanding, one could argue that its strength does not lie in the way it explores the tragic genre.
The tragic protagonist is defined by Aristotle as an admirable if flawed character, whose downfall evokes fear and pity. Although Macbeth was apparently a skilled and valued soldier and war leader at the start of the play, his transformation into an evil and ambitious character occurs quite early, and rather than appear a victim of an inevitable and unavoidable fate (unlike Oedipus, for example, who does not know that Jocasta is his mother), Macbeth quickly degenerates to a level of moral depravity. By the end of the play, rather than pitying him, many members of the audience feel that he fully deserves to die.
Thus even though this is a very powerful drama, it really does not explore the traditional genre of tragedy very effectively.