Ah, Macbeth, my favourite Shakespeare play (or, as I like to call it, "what if Claudius were the protagonist of Hamlet").
I have no words to properly convey how much I love it, but I'll try nonetheless.
The Macbeths have a great dynamic, what with Macbeth being courageous on the battlefield but cowardly and paranoid at home and Lady Macbeth seeming unassuming but being ruthless and conniving on the inside. It allows for a great contrast and subversion of traditional gender dynamics and just some wonderful banter - really, Shakespeare was amazing at it. It also establishes the theme of facades, which is very prominent in this play.
(No other characters are really fleshed out, but it doesn't matter in a play as great as this, just like the fact that the Macbeths didn't have a real plan and that no one ever suspected Macbeth for some reason and that Macduff was introduced towards the beginning and just kinda reappeared at the end to kill him. It's a short one, so what's it matter? Just wanted to point out the flaws so that I don't seem too biased.)
It gets even more interesting in Act Five, when they have gone too far to return and have taken many lives and are plagued by guilt, switching their personalities completely. Lady Macbeth becomes crazy and paranoid, perpetually hallucinating blood on her hands, whereas Macbeth becomes cold-blooded and tyrannical, laughing at the idea of being killed by a "man born of woman". There are also the elements of sleepwalking and ghosts, pointing towards the supernatural that is already present in this play but written off as madness instead - symptoms of guilt, showing that even seemingly ruthless schemers and warriors have their breaking points, for their hearts are still human, causing them to fear for their immortal souls and have pity for all those they step over. An interesting duality, one that has inspired many writers over the centuries, especially realists like Dostoevsky with the dark half. Speaking of the dark half...
Lady Macbeth is finely fleshed out with both humour and seriousness in such a way that made her arguably the most iconic character in all of Shakespeare and the type of character we would call a "girlboss" today, but Macbeth is still the star of the show. A brave warrior fiercely smiting his enemies, he's revered across all of Scotland, but even from the second scene, a sergeant notes that his sword was "smoked with bloody execution", showing that, despite all those around him calling him noble, his potential for corruption was right there under their noses. They will call him a vile murderer later for exhibiting the traits that have always lurked beneath the surface without their notice. It's still debated to this day how much of his darkness came from him being madly in love with his powerhungry wife and not wanting to seem like a coward and how much of it has always been there, a parasitic urge wanting to be unleashed, craving power for power's sake, striving and hungering, never satisfied with anything. He was a man of deep ambition, but also of deep folly, making him a tyrant and a terrible ruler who couldn't have ruled his country for more than two years at most. He hesitated and stumbled, but he was never the one to back down, always facing the challenges ahead of him. It's admirable, but it's also clear why it led him to his grave. It is the peak of tragedy.
I suppose I should talk about Lady Macbeth as well. She had a nice start, but in Act Five, the importance and humanity of her character is truly cemented. The complexity was always there, and she always loved Macbeth and wanted the best for him despite her persistent annoyance with him, which I think is wonderful. However, when she goes off the deep end in Act Five, we see her weakness for the first time, reminding us that, despite what her unending cunning and ambition may make us think, she's still a human being capable of feeling sorrow and making mistakes. There are hints of course (the scene from Act Four when Macbeth almost ruins the dinner because he sees Banquo's ghost sitting in his chair and Lady Macbeth desperately wants everything to go normally comes to mind), and it pays off brilliantly. The candles that burn the brightest burn out the fastest, a quote that applies to her and her husband, but probably more to her because she has less influence as a woman and non-warrior and therefore has to work harder, and it's morbidly fascinating to observe.
The comic relief is great too, especially the aforementioned and the three witches. Shakespeare really knew how to weave humour even into his tragedies.
Also, there are tons of amazing and iconic quotes. To quote a few off the top of my head:
"By the prickling of my thumbs, Something wicked this way comes."
"Look like the innocent flower, but be the serpent under it."
"thou cream-faced loon"
"tomorrow, and tomorrow, and tomorrow"
"Is this a dagger I see before me?"
And so ends this review, a walking shadow, a poor player, a review full of sound and fury, signifying nothing.