Roman Polanski's blood-soaked version of Shakespeare's Scottish play was the video version of choice when we were studying this at school, in spite of it having a nude Lady Macbeth and witches (and Keith Chegwin in the cast - he's Banquo's son).
Jon Finch has the lead and he is exceptionally good. Even a dagger which really appears to float before him (an effect not needed) doesn't spoil things. Odd that he never really got good movie roles after this. His Lady M is Francesca Annis, a spider of a schemer, also putting in a good performance.
Less adequate are Martin Shaw as Banquo, Stephan Chase as Malcolm, and Sydney Bromley as the Porter, although Terence Bayler gives good value as Macduff.
Perhaps this Macbeth is the first one to be truly cinematic, something that even Orson Welles couldn't achieve with Scots accents and Scandinavian settings. It remains memorable long after seeing and, in its excesses, opens up the text for a new generation, and finally, sees the repellent murdering usurper get what he deserves.
(Incidentally for perspective, the book 'Macbeth - man and myth' by Nick Aitchison looks at the real historic facts in accessible coffee-table book style).
